Dragonlord,
I would think you could take your pictures from any of the park's back access roads without being escorted. However, if you want pictures of rides from any other angle (out and around the rides, coaster tracks, etc...), you need to be escorted by a Rides Area Manager or OD.
I'd be careful where you post/distribute them though. The park's internet usage policy is pretty strict on it (if it's a picture or information about the park that a normal guest can't see or doesn't know, you can't share it).
Just my two cents...