parts, parts, and more parts.....

OK, getting heavily into the whole repairing myself thing. The few bike shops around here are hokey at best that I have found, and most are street based.... so it's the internet for parts, a few books and the internet for info and a lot of trial and error. Point being that I will be drilling you all for info :)

1. opinions on bottom brackets? prefer external bearings over internal? one size fits all when it comes to installing on the frame?

2. headsets... need some kinda puller to get the races out.. and do I need to do it?

3. Suspension bearings, how to replace those little bearings that are all dried up and making my rear end stiff (get the dual meaning there? LOL)