DC, are you using HEM or PT3? One thing you should definitely do ASAP is configure your HUD to display more stats. There are good tutorial videos on youtube under tightpoker.com's channel for both softwares. Different stats will become more important in different levels of play, and they will be dependent on your style as well. I play typical TAG in the micros (25NL), so some of the stats that I find useful are how often an opponent c-bets the flop (so I can get an idea of their initial c-betting range) and likewise, how often they fold to a c-bet on the flop (so I know if I can expand my c-betting range HU against them); also their 3-bet percentage (again, to define range), fold to 3-bet, etc. VP$IP and PFR are huge, but make sure your sample size is big enough. I don't put much stock in those stats until I have at least a few dozen hands. After I get at least a couple hundred hands on an opponent, I am wary of those stats.
Another important thing to consider is your stats at each table. Unless you're playing against regs that also likely have a strong read on you, you can exploit your current "table image" by looking at your stats. Say you just sit at a table full of unknowns and extremely tight players. After a few dozen hands, you've been dealt a lot of premium hands and have been firing away with many hands that never make it to showdown. If there are any unknown players watching your tendencies, look at your stats for that table/session to get an idea of what they see you as. Your VP$IP is likely to be very high, so you may be playing tight with a LAG image. Use that to your advantage. A disclaimer to this: if you're playing the micros, this doesn't apply as much. Most of the players are simply not paying attention and the regs usually have more history on you than this one session.
And finally, just because you have a HUD, don't forget to take notes. I run into a lot of exploitable situations based on notes I took previously that were more helpful than HUD stats.
Incidentally, what site/limit are you playing?