How many times you Voluntarily Put money In the Pot (VPIP) and Pre flop raise(PFR). For playing online pokertracker keeps more stats for you than most people know what to do with. If you are a B&M player you can go to their web site and get a good idea of the many stats they keep. Then you can decide what you think is important and go from there.
A very simple way I keep track of my live play is just to write down where I played, the date, time (hours played), my buy in, what limit I played at, what game ( Hold'em stud etc. )and whether or not I made or lost any money. Then the next day I try to go over some of the hands I played and make notes on any areas I can improve or areas i did well. Not exactly scientific, but I know how far up or down i am for the year at any given time.