converting coordinates

Hey, guys. I feel stupid at not being able to remember these formulas, but
math is not my strength. Can someone give me the formula (again) for
converting latitude/longitude coordinates from 00.0000 degrees to 00 degrees
00 minutes 00 seconds, and vice-versa! I've actually asked this once
before, and got a clear answer, but I forgot to save the info.

Thanks for your help.

Jason Fry
Computer & Math Doofus