First the biggest paintball site around is PBnation.com
Second Hit up Pbreview.com to check reviews of guns, paint, air systems etc.
Third there are a lot of great priced sites. Actionvillage, Xtremepaintball.com etc.
Fourth I would not suggest you start out with a gun that can ramp (ie multiple your trigger pull to give you 15-30+ balls per second). If you start with ramping then I have seen way too many people depend on ramping to play and not get down to the skill of the game... plus its much more expensive as you have to buy a loader that is motorized etc.
Start with a simple gun Ie Tippman, Piranha, sypder etc. Learn it and work your way up.
I had about a year ago jumped form my gun to a Dangerour Power Fusion.. Its now insanely fast if needed, and accuracy is awesome.. The price was only $450 and compared to guns in its class (build, accuracy,speed,) its at least half the price. The customer service level from DP is insane.
Anyway start out researching around. If you get talked into an Ion at least look into what you have to spend to get it to optimum working/reliability levels... also before you buy one consider how hard it is to take apart and maintain.
Good luck the sport is beyond fun. It can get costly but it doesn't have to be if you don't turn your gun on ramping, and don't rely on mass quantities of paint to get your kills.
There are some really big games that are great if you get into scenario as well. Michigan has some at hells Survivors (global conquest, Monster Game, Tippman vs World) as well as D-Day (Oklahoma), and many more.