Hey guess, how is it going. I need some advise, this is my situation. I been trying to put my computer for the past 7 hours. I am stuck.

Ok,
1. My mobo is an ATX, and my power supply is an EATX. What should I do?
2. What colors are positive and negative. I know Black in negative and red is positive, but what about when its green and white, orange and white, and so forth?
3. I notice that my AMD 64 4000 (socket 939) heat sink came with a little paste on the heatsink it self. Should I buy more, or just leave it like that?
4. My case came with two wires that are blue. They look like thermoniters. They are connected to I believe its a screen in front. I have the Lian Li PC-7. Where do thos wears go, and how do I tape them there?
5. My computer doesn't turn on, I have 480 watts. Its an ANTEC true blue 480. If any advice possible it would really help. Thanks.............