Resource that will tell me what my PokerTracker stats mean?

[el_grande]

Can someone point me to a site or even a post here that explains what percentages you want to have as a tight-aggressive LL holdem player when you look at your PokerTracker stats? The only number I know is to try and call 15%-17% of hands preflop, but there are so many other stats on there.

Thanks.