Bike Parts

Does anybody know a site that will tell you each part of a bike is and what it does.

well depends which bike the best thing to do is have the manual but you can get online manuals

http://www.howstuffworks.com is a great site. I've been trying to learn alot more about motors and different things on bikes and that site really does break everything down so its very simple to understand. Check that site out and I'd be willing to bet it helps you learn something. I want to learn how to fix bikes and a good friend of mine told me something thats really helped me alot. "If you don't know how something works, how are you gonna fix it?"
Read and read. Theres tons of great information on that site and internet forums are also a great place. I've only been on here a short time but I've been reading posts and threads and am already learning more and more. Don't be afraid to use the search button too. Chances are any questions you have have already been answered several times.

Here is a direct link to the how motorcycles work on that site. This should help explain how everything works. I'm rereading it myself right now because theres always things you seem to miss the first time you go through it.
http://auto.howstuffworks.com/motorcycle.htm