Seapony's trials and errors... mostly errors.

[daplatapus]

Lookin' good! When the tank is first set up and you're getting things running, the cycle is the first hurdle you'll have to wait through. During that time you want to be testing for Ammonia, Nitrite, then Nitrate in that order of time progression. Phosphate, IMHO, is a bit of a symptomatic thing. If you're concerned if your rock is leaching it, or there's an accumulation from feeding foods with phosphate in it, you can confirm your suspicion with a phosphate test. But more times than not, you'll test but read 0 because the algae growing in your tank will have used up any free phosphate. So while it'll be a problem, your tests may not read any.
The next big 3 are Magnesium, KH and Calcium. You probably don't need to worry about these until you start putting coral in. The fish don't really care. Of those 3, you have to be concerned with your Magnesium 1st. It's level determines your tank waters ability to hold your Calcium and Kh stable and at the proper levels.
There's some great reading material here:
http://www.canreef.com/vbulletin/showthread.php?t=21968

http://www.reefkeeping.com/issues/2006-06/rhf/index.php

And as always, if you need clarification, just ask. Lots of science nerds here There's never a dumb question.