The Buffalo Bills are a good example. They usually have two sessions a day. The players sign on their way to and from each of these sessions. After the second session, the players head back to their dorm room. Don't worry, the autograph hunt doesn't end yet.
Many teams have evening meetings, so plan to make a day of it.
The Buffalo television stations have interviews with many of the players for the six-o'clock news. Find out if there are any daily shows near you that always have a live-interview. Most of all have fun. I myself get upset with a bad day, regardless of what you get, use the day to get a chance to see these guys without helmets and pads, this will help you after games during the regular season. Training camps are also a good time to meet other collectors.