CVS help



Can someone out there help me get CVS working with Emacs?  I have some very
basic questions (where do I put the SSH key?) and some more advanced ones
(like how do I put in a small patch to the current CVS version without
losing the more extensive but untested mods I'm making, etc. etc.).

I have been using TortoiseCVS for simple stuff, but it doesn't seem to be
sufficient....

(Details: running CVS 1.11.6 under Cygwin on Windows 2000; Emacs 21.2.1)

Thanks,

              -s