In the immediate vicinity: Ben Davis Paintball, Proving Grounds.
Others: Paintball Heat, Badlandz, Paintball Valley, Asylum Extreme, Paintball Barn, Third Eye PB
They do a great job of maintaining a safe and family-friendly environment. A 10-foot-tag rule is in effect during open play, so you don't have to worry too much about the little ones getting nuked. The regulars are a good bunch and are happy to help a willing newb lean their way around.
Looking at the crowd, you'll usually see a pretty good mix. Everything from 'hard-core' SpeedBallers, to camo-shrowded/mil-sim WoodBallers, to a family with Sunday brunch in the staging area.
The fields are in a primarily wooded area. For the most part, you get to play in the shade ;-)
The monthly 3-man series is perfect for a team to break into tournaments. But, it also draws teams/players from a wide range of skill levels.
Whether just starting or a seasoned veteran, I also recommend this field to any player.