The Netherlands is a popular destination for British people, both for vacations and for work. You can read more here.
I have always found Dutch people to be friendly, welcoming and open. When I lived there it was one of the places with least racial prejudice that I had experienced. My impression is that it has become a little anti-Islam since then, but nevertheless still very welcoming.
One the the reasons for the openness is religion. The country is mainly protestant, and not Church of England style protestant, so that there is a tendency for proving that one is living a non-sinful life and are hiding no secrets. One sign of this is that people very often have their curtains open, so that you can see into their living rooms (not usually bedrooms) day and night, even though they live on the ground floor and know that they can be seen. In my time there, I saw all manner of goings on, unintentionally, just by walking down the street.
Dutch is not a complex language: the size of the vocabulary is not large compared to other European languages. Yes, nouns have gender, but the other rules of grammar are not so complex (unlike German and Slavic languages). In many ways it is similar to German, but there are a lot of French loan-words, and English has a lot Dutch loan words, so if you know any other European languages, you will find Nederlands relatively easy. There is also a trick to simplify the grammar: male and female nouns can be changed to neuter by making them diminutive (hondje/doggie, broodje/bread-roll, etc.), and these diminutive forms are therefore in widespread use.
Pronunciation of Dutch takes a bit of practice, due to the guttural sounds made by "G" and "CH", and a few unfamiliar sounds; at first it will make your throat tired.
Dutch people are also excellent at other languages, and the average person will be able to converse in several foreign languages, so you will be able to communicate with people before you learn any Dutch. The reason for their language skills is simple: almost all TV and movies are shown in original language (Dutch is only spoken in The Netherlands and part of Belgium, so it is not cost effective to dub the material) with Dutch subtitles. This means that people in the Netherlands learn foreign languages from birth. A word of warning about movies, though: children's movies are often dubbed.
I found the cost of living to be fairly low. Groceries are fairly cheap, eating and drinking out is also quite reasonable. Accommodation is not expensive. Public transport (busses and trains) is also not expensive.
I found accommodation to be in plentiful supply in the town where I lived (Leiden). Some areas are not so well supplied, though, meaning that prices can be higher. You can rent apartments and houses, both furnished and unfurnished. I found my apartment quite quickly, through an agency.
For short term accommodation, there are also a range of holiday lets: rooms in guest houses and hotels, self-catering flats, etc.
A friend of mine lived for several years on a house-boat, which is an option worth considering. The only downside that she complained about was that, in really cold weather, the waste pipe (sewage and from showers and sinks) would freeze, since all pipes go though the water when they leave the boat. Luckily, The Netherlands doesn't have the kind of hard winters that occur in places like inland Germany, because it is by the sea.
It is not uncommon for apartments to have only showers, and no baths. If you really want a bath in your flat, you may have to search for longer. Another thing that many apartments do not have is an oven. Oven cooking does not seem to be a part of traditional Dutch home cuisine. Some things can be cooked on a stove top in a Dutch Oven, but some things (like bread, pizzas, cakes, soufflés) are next to impossible in a Dutch Oven.
The Netherlands is well supplied with hotels, at all possible prices. I have used a number, and found them, in general, to be good quality, clean and cheap.
Public transport is excellent in the Netherlands. There are trains, which run frequently, and are inexpensive; I never had to reserve a seat, as is usually necessary in Germany. There are plenty of busses, and some cities like Den Haag and Amsterdam have trams too.
For busses and trams, most towns have a card-based payment system: the OV-chipkaart. When I was there they had a stripe-card system (where you stamp the appropriate number of stripes for your journey), but I think that has now been phased out.
The Netherlands has good roads, well signposted and well maintained. Note, however, that they have speed limits and enforce them.
When I first arrived, the Dutch had just discovered roundabouts, and didn't understand the principle, so traffic entering had priority over traffic already on the roundabout; a recipe for gridlock. That changed very quickly, and roundabouts now function the same way as in Britain.
I found quality and availability of medical services to be excellent in The Netherlands. Whilst there, I had cause to visit a doctor (GP) several times, had an operation on my ear, and had inoculations. I had no complaints, and there were no language issues.
The cost of medicines was quite reasonable, and everything is available (with a prescription, when appropriate).
I had some very good restaurant meals in The Netherlands. There is a vast range of options, due in part to the number and variety of immigrants. The Dutch seem to have no problem with spicy food, so the flavours were not tampered with. I had excellent French, Italian, Indian and Chinese cuisine while there.
One of my favourite Dutch dishes is satay; I like Dutch satay more than any that I had in Thailand or Indonesia. I am also quite partial to Maatjes (Soused Herring - not to everyone's taste). Another food that you find on vans and kiosks is loempia (a kind of Indonesian spring roll - lovely).
I found grocery shopping to be very good in The Netherlands. I quickly found where to go to buy everything I wanted. The shops and supermarkets have great variety, good quality and fair prices.
Spices and herbs are much more readily available in Dutch shops than in Germany; the selection in Germany is sometimes rather limited. There are also some Dutch specialities, some of which I miss, such as Sambal Smeerkaas.
One thing that is fairly common in the Netherlands is ticket-based queuing. English and American people may find this confusing, at first; it is a way to compensate for the fact that locals can't queue (no-one can queue like the British, after all). You may find it is bakeries, butchers, delicatessen counters in supermarkets, and in some government offices. It is not unique to the Dutch; it is common in Germany, and they even have it at my local supermarket in Malta. Basically, you pull a ticket from a dispenser roll, and wait until your number is called or displayed.
Registration is required, but is simple. Local and federal registration is done together, at your local council offices (Gemeente). If they need additional documentation, they will contact you, otherwise they will send you a bank transfer form to pay the fee. If you change address after applying, before you pay, then you can just go to your new Gemeenteraad or the police station and tell them your new address. This may take a couple of months, but don't worry: no-one is going to come to your home or office to harass you, or arrest you on the street for being late completing your registration.
You should probably try to get a local bank account before they ask for payment, as it makes it easier and cheaper to pay from a local account.
Generally, banking in the Netherlands is good, but there are a couple of things about the Dutch banking system that you may find odd. One is the concept of trusted payment recipients. There are a number of organisations which are considered by all banks to be trusted: government departments, the post office, the post-code lottery, etc. They can take money from your account without presenting your bank with a signed mandate. Payments are done by direct debit (i.e. initiated by the recipient). This means that you can't cancel these payments by contacting your bank. You also can't have organisations removed from (or added to) this trusted list; all you can do is ask your bank to turn off all trusted payments, which can have some negative side-effects.
My experience of Dutch police was very good. They are friendly and helpful; they are approachable; and they mostly don't bother you. I never had any issues dealing with the police in English. The only problem that you might have is to find a policeman; unlike Germany, they tend to stay in their police stations unless there is trouble, even though the ratio of police to population is at the top of the world rankings, along with Germany.
The only dealings that I had with the legal system were in getting my divorce, so fairly limited. I found my lawyer to be very professional and sympathetic, and the court handled my case quickly and painlessly. I have not heard complaints from any of my friends or colleagues about the legal system there.
Dutch income tax is at about the same rate as German tax. This means that (depending on your earnings) your total deductions, including social insurances, will be about 50%.
Tax and other contributions are levied on a PAYE (Pay As You Earn) basis, including for freelance contractors. The situation for contractors is that, in effect, they are no longer legal, and everyone needs to have an employment contract, with PAYE tax and other costs deducted by the employer (usually your agency), plus vacations (with pay) and paid sick leave. This has made contract work in the Netherlands more complex, and less lucrative.
Most homes have cable TV, and for rented accommodation it is typically included in the rent. There are only a few Dutch channels, but very many foreign channels (English, French, German and Italian). Great for helping you to learn another language, but not actually very entertaining, I found.
Movies are almost exclusively shown in the original language, with Dutch subtitles. The exception is children's movies, which are often dubbed (seeing "Babe the Pig" in Dutch with my kids and a girlfriend, with me having to try to translate everything simultaneously, was extremely hard work). Showing them in original language means that there are no delays before films are released (no delays while they are dubbed). A Dutch colleague once told me that comedy movies were especially good, because when there was a joke in the original language which did not translate, the dubbers replaced it with another joke in Dutch, so that he sometimes got two jokes when I only got one.
Telecoms services in the Netherlands are good, and there are an adequate number of operators. When you move there you will find good mobile roaming services, and when you decide to get a local mobile phone service, you will find a wide choice (including flat-rate services, conventional pre-paid services, and traditional post-paid services.
Mobile and cabled coverage is very good, mainly due to the high population density.
Most rented apartments already have Internet included in the rent, but if you buy a house or flat, or rent a place without Internet, there are good options available.
The Netherlands are famous for legal drugs. In fact, it is only cannabis that is legal; other drugs remain illegal. This link has more information.
When I lived there, things were very easy going, but have since become less so, partly due to pressure from other (less progressive) nations. Coffeeshops (where you can buy cannabis in various forms) have become less widespread; some have stopped selling other products (coffee, food, beer etc.). Many now only sell, but you cannot consume your purchases there. There are also some provinces where proof of residence is required to purchase - of course if you are living in the Netherlands, and registered, this is not a problem.
The Dutch have a very progressive attitude to pornography. It is not hidden away in secluded rooms, and people are not ashamed to be seen browsing explicit material. Light porn is shown on public TV channels at night. Adult magazines and DVDs are widely available, and largely uncensored.
The government's attitude is that making it easily available makes it less likely that young people will have sex just because of curiosity. The statistics bear this out: The Netherlands has one of the highest average ages in the world for first sexual experience.