Not to sound, er, mean, I guess, but perhaps you should try a normal arduino out first. It seems your missing a lot of basics, which you will need, even for a project as seemingly simple as yours. I would get an arduino 2009 (Duelmilanova, i think, but that is probably spelled wrong), along with an accelerometer, and use that to "prototype" your idea... A starter kit would be even better, because that would give you a good intro to much more than just one specific thing you can do with the arduino:
^there are a number of such starter kits, but I like this one, because it comes with nice instructions... it does not, however, include an accelerometer, but you can always pick one up at sparkfun.com