Any computer dudes out there?!?! Help!

You can power up the power supply by shorting the green wire to the black wire next to it on the 20 pin connector. If it runs then the power supply is ok.
Make sure the motherboard isn't plugged in while testing power supply.

http://www.helpwithpcs.com/courses/power-supply-basics-inc-pinouts.htm

If it powers up, and it's a new m'board then ram or processor change is the next step. or follow what 66dvert posted.