I just got a digital multi meter, and ckecked my 5 & 12v lines, and my questions are:
is 11.95v on the 12v line ok?
is 5.2v on the 5v line ok?
how do I check the 3.3v line?

PSU FAQ

That PSU Faq answers all three of your questions.

12 and 5 are fine, and im sure there is a guide somewhere you can read bout the 3.3, i dont kow for sure

bugger, they already had it posted hehe

3.3v line are the orange wires on the atx connector

also remember the wattage ratings,a400 watt power supply can be better than a 600 watt supply if the 400 watt has a better 12v amp capacity than the 600 one,lots of cheaper power supplies have a inflated 5 and 3.3 rail but the 12 volt rail is most important,i have read this from numerous research pages.