basic stamp would be easyist to learn to program if you have no experience, however the bare bones board is cheapest at only ~15 dollars, i would buy a basic stamp 1 or BS1 for short. its only around 30 and the software is easy and free to download... some of the other guys here would probably recommend the bare bones board though. i don't have much experience with it.
Check around, this web forum and google for some basic software.
Truckstop