I wouldn't listen to sean either. If you're not playing the limits over what the microstakes version tracks, then don't buy the full version, there is no reason to.
As far as learning how to get the most out of it, just search around the forums...nearly every aspect of pokertracker and holdem manager have been covered somewhere here, so there is really no need to repost it all. Search for things like "best HUD stats" or "HUD layout". Those will help you with some of the best things to have in your HUD. For a good resource on what all of those stats mean and what the ranges tell you about your opponents, check out my guide here (http://www.cardschat.com/f57/special-1k-post-holdem-manager-stat-166475/). It says that it's for Holdem Manager, but it is really for any poker tracking software. That is a huge problem that a lot of people(including myself) have...they have their HUD set up perfectly, but they don't know what exactly they're looking at.