Hehe, thats kind of like trying to explain how the car transmission your neighbor designed in his basement works. Every robot's different, and
complicated. However, there is hope! First of all, heres a good link.
http://www.chiefdelphi.com/forums/papers.php?s=&categoryid=2&perpage=10&direction=DE SC&sort=date
CD technical whitepapers. That'll get you in the right direction. I know you can't look at every one, but I probably have browsed through 60% of them in the last couple of months.
http://firstrobotics.uwaterloo.ca/resources.php
This is a good one. It's got a bunch of pictures of great robots, and some power points with the basics. I
have looked over all those pictures; it's too hard not to! They've got some basic powerpoints detailing stuff.
Everyone keep adding links!
__________________
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-Sir Francis Bacon
"Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius -- and a lot of courage -- to move in the opposite direction."
-Albert Einstein