PokerTracker

I play single table micro limit SNG's only. What stats should I be collecting that are particularly relevant to this kind of tournament. Is there a priority list of most important to least important stats.

It really depends what you want to know about your opponents. If there's something particular that you want to know we'll be happy to guide you towards the correct stat(s), but for general advice and discussion about this kind of thing you'll probably get more help in a strategy forum like those on 2+2.