http://www.bitcomet.com/
This was the best and easiest to use of all the client software that i have tried. It is fast, resource light and has no spyware. It should be easy enough to learn how to use with the included help files and such. If you have any problems, IM me on yahoo. I can tell you where to get the best torrents and such or give pointers on the program.
Direct Connect is another alternative once you build up a library of things to share and want to hang with a more exclusive and refined crowd. The best client for that is DC++ http://dcplusplus.sourceforge.net/ . Ditto if you want to learn how to use and abuse that.
BITwise is a P2P messenger program. If you want to share things with friends without getting your feet wet in the muck of sharing with strangers, I enjoy using it more than any thing else. You can set up a buddy list and file permissions and the whle nine yards without half the hassel of the others. http://www.bitwiseim.com/
Those are the three best ways I have found of sharing things other than Gmail or IRC. It's a time consuming hobby, but can get you some very good results and entertainment.