First thing you need to do is find out what the legal hunting age is in your state.  Where we live it's 10 years old.  As soon as my son hits 10 next February, he will be signed up for the Hunter Education course. It's different for each state. In the meanwhile, my son has been joining Daddy as an observer since he was 4.  Obviously when he was smaller, we didn't expect him to sit still for too long, or sit quietly for too long.  Hunts were always short.  As he's gotten older, he can sit quietly for longer periods.  If they display a love for the sport, encourage it!  They are the next generation, and they are never too young to learn to love the outdoors!

He can't actually hunt until 12 in our state, I just wondered if it was too early to be exposing him to the actual process (shooting, tracking, gutting, etc)of hunting. I had some friends give me a hard time about it.

I find that people tend to object to stuff they don't understand.  Just like people will give you a hard time for hunting, they will give you a hard time for "exposing" your son at a young age.  You have this wonderful little boy who is interested and excited....the best thing you can do it take him! Not only will you be teaching him the process, but you are investing your time in him! The memories you are creating with your boy are priceless! You are also teaching him to love and respect the outdoors! Besides that, I firmly believe that kids who are out in the woods hunting with their Dad (or their Mom in my case) aren't off getting into trouble. Keep on doing what you are doing!!