My first trips were Hollister Hills, they have lotsa stuff to practice on from gravel roads to obstacle courses to tank trap. I loved Jungle Trail when I was stock with a locker and 33s. I also agree with everyone about following someone who knows what they're doing (that's how I did it) but also someone who has a similarly built rig. You don't want to follow the guy linked on 40s cause you probably won't be doing what he does...
I'd also recommend wheeling without a bunch of work on your truck first. I feel like I know my truck a lot better because I was hanging wheel and driving with unhappy front springs before I went 37s, geared case, etc. It really teaches you the limits of your vehicle and how to actually wheel, not just build a badass truck and try to point and shoot.
