Im sure there are plenty here that know much more than I do, but you can start here: http://www.grtu.org/

You dont need a guide per se, but it will help ifyou've never fished here before. There are good fishing spots that are public access, however if you can get with a TU member they do have Members-Only lease access locations that can get you into some great fish, and they can get a few 'guest' passes to bring a non-member when they sign up to the lease program.

Its been years since i've been down there to fish, but if I recall the fish like small flies and are spooky. The river bottom is slick in spots, if you have boots with studs i'd bring them.