As a position player I usually get to field around 1. Like Tom, it's important to take care of your body. Usually why most of us get to the ball park so early. That and preparing that that days pitcher/hitters.
If I am pitching I show up around 3:30-4 and usually just hang out until i hop in the hot tub and start getting ready at 5:30. If i am not pitching I get there around 1 and do what ever running and lofting that is scheduled for that day, shag bp, eat food and watch a ball game.