Good day. I'm trying to get the parts to build a desktop computer. I've got a few questions:
1. What determines what size (watts) power supply I'll need?
2. Is it better to have case fans for fans for the individual components...a fan for the RAM, a fan for the hard-drive ect....

Thank you in advance and have a good day!

450w minium - 550w if you are running a decent graphics card. 650+ for a very high end graphics card

Buy a good one - cheap ones lie about thier wattage. a good 450w will own a cheapass "650w" in actual real life output

go for dual/quad 12v if available.

Thanks for your response. How about question #2?

tunnels are the way to go

ram fans = stupid. use ramsinks or nothing