what is a PSU? sorry i'm a freakin noob... cpu is central processing unit.. so psu must be like... p____ secondary unit or something... lol i dunno.. what is it!!!?
^^^ yep. supplys power to all your parts. the more watts it has, the more it can power. (i.e 400w PSU>250w PSU)
this site tells you how much powerful you PSU needs to be for all your parts http://www.jscustompcs.com/power_supply/