Rally is so much fun - way more fun than traditional Obedience. The best part is being able to talk to your dog, so don't be afraid to talk as much as you want.
I downloaded the signs off the AKC website and made flash cards with them (which is helpful in the Advanced and Excellent levels when there are some weird ones). I used the flashcards at shows after we got a copy of the course to refresh myself on the sign and any specifics about it.
I also made full-sized ones and set up courses in my driveway to practice on. Click on my signature photo for a link to our Youtube channel - there are some videos of Red and I practicing Rally, and also videos of actual shows too, which I annotated with the signs so you can tell what we are doing.
You'll want to make sure you and your dog can do the exercise on one sign before stringing a bunch together. Then work your way up to doing more and more together at a time. Practice off leash too, if you can, since you'll probably move through Novice really quick and get to Advanced when you have to be off leash.
I thought about going back for our RAE, but it just became more of a money sink at that point. We already have the RN, RA and RE so I didn't really feel like it was necessary to do the RAE - maybe if I had unlimited funds and time for shows, but sadly that's not the case!
Good luck, you will love it