Grumble,

No offense intended, little buddy, but from your questions, I fear you may be heading a mite out of your depth.

However, if you want to persist ( and I, most heartily, urge you to do so), try these sites (particularly the third one:

http://www.mcmanis.com/chuck/robotic...dge/index.html
http://robotroom.com/HBridge.html
http://www.foxflier.com/stuart/radio.htm

Then if you start to feel a little befuddled, try this one (i'll bet it will be the most help to you) :

Dave Lancaster's http://darkith.dyndns.org/~darkith/

Good luck.