Here's the layout of my UK laptop keyboard (sorry for the fuzziness - phone camera and a bit dark to be taking decent shots):
Main differences are:
1. £ symbol on 3 key (option-3 gives you #)
2. € symbol on 2 key
3. ~ is in a different location (between left-shift and z key)
4. Return key is on two rows instead of one
5. \ and | key is just above the right shift key (where the return key would normally extend on a US keyboard)
There are possibly a few others as well, but that is most of them. (Oh, the keys aren't labelled caps lock etc and instead show the symbol).