There are a large number of photo galleries in this web-site, under "About Me" -> "Trips & Events".
There are two possible variants of these galleries: those which display thumbnails in a vertical preview pane (on the left), and those with a horizontal preview pane (at the bottom). Apart from the different layout, they both work the same way. At the time of writing this Help page, all galleries have a vertical preview pane.
The photos & the thumbnails are all of reduced resolution, to improve the speed with which the photos load. The "full size" photos are typically 1000 pixels by 750 pixels; The thumbnails are either 130 pixels wide (vertical preview pane) or 100 pixels high (horizontal preview pane).
When you open a photo gallery it can take a few seconds to load all the thumbnails into the preview pane and to load the full size photo into the main pane. There is also a short delay each time you select a different photo to see "full size". If you have a low speed Internet connection, the delays may be longer.
You can use the cursor keys to select the previous or next photo. For galleries with vertical preview panes, use the up and down cursor keys; for those with horizontal preview panes, use the left and right cursor keys.
If the cursor keys do not select the next or previous photo, this is because the main frame (where the gallery is displayed) no longer has the focus. Simply click somewhere in the gallery, and then the cursor keys will work again.
There are arrow buttons at the start and end of the strip of thumbnail photos in the preview pane, which you can use to select the previous or next photo.
If there are too many photos to fit in the preview pane (usually there are), the pane is scrollable. You can scroll to the photo you want to display in "full size" and simply click it. There are also tool tips (pop-up text) on each thumbnail to describe it. After clicking a thumbnail photo, not only will that photo be displayed full-sized, but that thumbnail will be centred in the preview pane, and be highlighted.
If your browser supports it, you can view the photo in "full size" by right-clicking on the large photo (not on the thumbnail) and selecting "View Image" from the menu which pops up.
Although most pages on this site can be viewed in a window of their own (by adding "?noframechecking=1" to their URL, this is not possible for photo galleries. If you try it, a JavaScript error will result, and the gallery will not display anything.