Prague is the capital of the Czech Republic. Living in the city is rather different from living elsewhere in the Czech Republic, which is why this article is about living in Prague, where I lived, and not about living in the Czech Republic.
It is quite a while since I lived and worked in Prague, and since then the country has joined the European Union, so some of my information may be out of date.
I found the Czechs to be friendly and welcoming. The country was a significant part of European history, and the people are understandably proud of their history. With some notable exceptions (e.g. Brno, the Russian Mafia capital of the country) the country is law abiding, peaceful and safe.
Prague is notably more expensive for many things than the rest of the country, and this is especially so for accommodation. There are companies which specialise in apartments for ex-pats, equipped to higher standards than the general accommodation market, and these can be very expensive (I found prices higher than in Munich). Having said that, these ex-pat apartments can be fantastic: of all my colleagues, I probably had the least fancy place to live, because I got tired of searching quicker than the others.
If you use the agents that the locals use, then prices are lower, but then standards may also be lower. Using such an agent is much easier if you speak Czech; alternatively you can take a local with you when flat hunting.
When I was there, it was still legal and common practice for there to be two prices for apartments, hotels etc.: one for locals, and another higher price for foreigners. Membership of the EU has now largely stamped this out.
There are the usual range of international hotels. Prices and standards are pretty much the same as everywhere. I and my colleagues were at the Hilton for 6 months, and it is a nice hotel, comparing well with Hiltons in other cities.
If you go down market a little, there are a good range of reasonably priced hotels that are clean and comfortable, but, as with anywhere, once you go down past a certain price you will be in the territory of cockroaches and bed-bugs. Finding a suitable hotel requires some time looking on the Internet, comparing prices and checking reviews.
Taxis are somewhat cheaper than London or Munich. A friend once missed a flight from Prague back to Munich, and since he was in a hurry, took a taxi; the taxi ride was cheaper than the flight. After that it became a regular thing amongst by colleagues, especially when several people were travelling together, which made the cost savings even greater.
You do need to be careful with taxis though. Make sure that they turn the meter on. If you are unsure about the cost, then ask the driver what the fare will be before getting in, and if you don't like the answer, ask another. Taxi drivers in Prague do have some room for negotiation.
Public transport in Prague is actually very good. There is an underground train system, and an excellent bus and tram network. Prices are quite reasonable. You can read more here.
I found Prague, and the rest of the Czech Republic, nice to drive in. I drove quite a lot there. Signs are good, and road quality is also good. Petrol (gas) stations are frequent and have western style shopping and catering. As in all cities, parking in some areas can be a nightmare.
The autobahns/motorways have speed limits (130 kph). Elsewhere, the speed limit is 50 kph within towns and 90 kph outside of towns.
Cars with foreign registration seem to get stopped by the police more often than local cars. There are on the spot fines (my first fine was €5 - ooh!). The amount of some fines seemed to be discretionary (you know something is wrong when the opening question from the police is "How much money do you have?"), and then it really helps to have a local with you to negotiate the fine down.
While I was in Prague, I was told that, due to budget issues, most police cars were rationed to 3.5 litres of petrol per day, so if you were chased by the police, just to keep driving and they would have to give up after a couple of miles. I am not sure that this was really true at the time, and am pretty sure that it is not the case now, so don't try it.
Most Czech people in Prague speak English. In some parts of the country (e.g. Sudetenland), German is still more common than English, but I actually never had a problem communicating in English.
Czech is a Slavic language (in the same family as Russian, Polish, Serbian, etc.). For most native English speakers it is hard to pick up Czech, but the way it is written (Latin alphabet plus lots of accents) makes it easier than Russian.
One of the great things about written Czech is that there are very clear rules (with no exceptions) about pronunciation. All syllables are exactly the same length unless there is an accent to indicate that it is longer (e.g. ó) or shorter (e.g. ì), like speaking in time with a metronome. This means that, once you work out the sounds that the various letters make, and how to deal with words which seem to have not enough vowels (like Plzeň or Brno) you can read and pronounce Czech accurately even if you have no idea what you are saying.
Due to their history as part of the Soviet Union, Czechs hold a huge grudge against Russians and the Russian language. Before the Iron Curtain fell, everyone had to learn Russian at school, but nowadays most will not speak it or even respond to it. So, if you can speak Russian, don't use it; stick to English or German (the most common second languages), unless you want to risk a fight.
Prague has generally good medical services, but there are some issues.
As an ex-pat, with good medical insurance or the funds to pay privately, you can get the very best care in well equipped facilities, no language problems (consultations in English or German, and sometimes other languages) and minimal waiting times, but it is not cheap.
If your funds and insurance are a limiting factor, and you need to use the same medical services that the locals use, you are likely to have to wait, and may need a friend to act as interpreter. Nevertheless, the quality of care, and of equipment, is good.
Prague has some really excellent restaurants (although my favourite closed due to the floods a few years back. Top-end restaurants are just as expensive as in most big cities, so don't expect a bargain, but the quality, service and variety that your money buys you is really very good. Our (I and my colleagues') favourite restaurant (the one that is now closed) was on an island in the river, and we went there a lot (and spent a lot of money there), so when they started to run out of the wine that we always ordered, they kept a small stock back just for us.
If you go down market just a little, you can get some really good meals for reasonable prices. If you get out of the city, you can find fantastic meals at bargain prices.
At real bottom end of the market there are very cheap meals, for example in Czech pubs. You just need to be prepared to experiment a little.
Typical Czech food is not so different from German food: duck, pork, red cabbage, dumplings (Knedliki), sausages and rye bread. One thing I don't recommend is "Beer Cheese": although there is lots of stuff on the Internet about this, describing it a a cheese based dish, what I saw was made from the fat on a pig's head - not for the squeamish.
I found grocery shopping to be fine in Prague. There are local shops and supermarkets, and also some international supermarkets (e.g. Tesco), so you can get familiar goods or local specialities, as you wish.
Of course, shopping in local shops can be harder when you don't know the language (unless there are pictures on the containers), but it doesn't take so long to learn the food words that you need. You can always use you mobile phone to translate.
The Czech police are not particularly scary, unlike American or sometimes even German police. Nevertheless they do stop cars quite a lot. At the time that I was there, I had a British passport, a Dutch driving licence and a German registered car and insurance; this used to freak out the police; they were sure that something was illegal (there wasn't) but couldn't work it out as they couldn't read most of my documentation.
As a pedestrian I was never stopped or otherwise bothered.
Income tax is fairly reasonable in the Czech Republic: a flat-rate of 15% of gross income. On top of this there are social costs (Pension, Health Insurance, and Insurance against Unemployment and Sickness) of up to 13% for the employee. Compared to Germany, the Netherlands and Scandinavia these rates are trivial.
Local TV is (unsurprisingly) in Czech. If you want other languages you will need a satellite receiver. Most more expensive apartments include satellite TV, but if you are at the lower end of the market you will need to get your own. A better option is probably to subscribe to a streaming service (along with a VPN service to make you appear to be in the necessary country for your streaming service).
There are three proper mobile operators in the Czech Republic (T-Mobile, O2 and Vodafone), all offering a full range of services (from 2G to LTE), so you will almost certainly have access to cheap roaming deals when you arrive.
There are also, for historical reasons, a lot of WiFi service operators.
When home Internet was first introduced there, it was very expensive, but has become relatively cheap. For example this link contains some prices for cable Internet which are cheaper than I pay in Munich (for lower speeds).