The one at Cubefreak had a lot in it
http://cubefreak.net/glossary.html That's a good glossary.
As mentioned, the lettered permutations are just movements of certain cubies which are named so for better recognition.
You may find other names for some of them though. Take the A/U Perms, no one calls them them, but corner/edge 3 cycles. (don't ask me which is which, I don't know which is the A or which is the U)