Here's a quick overview of
player types.
Honestly, unless you have a large hand database in Poker Tracker, don't worry much about using it to determine your opponent's playing style.
Again, PT is usually going to be most useful to people starting out in analyzing their own statistics. Check the micro limits FAQ for a guide on what your stats should be.
Most books will talk a bit about what type of player your opponent is when taking actions. Such as, don't try bluffing if you're up against a player who will call all the way (that is a loose/passive player) and don't go to war with a rock (a tight/passive player). They may not come out and all someone a tight/aggressive or loose/aggressive player, but you'll find references all throughout the literature.
Regards,
T