I had already been in obedience for a year or two before Bud Kramer's Rally Obedience was proposed as an new sport, and adopted by the AKC.
I was delighted with it, as it was derived of many of the "doodles" that trainers used to teach heel position to their dogs. Sadly, in the novice obedience classes I attended, heeling was a jerk - pop - and taught my beloved to lag even more!
The rally classes help to change that, I could encourage and praise, repeat a command and she learned (finally!) where heel position was ~ and wasn't.
Before long we had our heeling act together and progressed through the levels.
These days, my dogs are trained in rally exercises as an introduction to heeling, and when done well, rally is beautiful to watch!
Am curious about and want to try Rally in other venues (besides AKC), ASCA and UKC are also available on occassion here in Georgia...
My advice to those wanting to start, get a copy of the signs that will be used in the venue you would like to trial in and learn them. Take a class, or find a group that is doing it and then train the moves to your dog. Get out in various environments to practice. You really don't need signs for that, just walk along heeling with your dog and ask for a come front and finish right, a down -stay while you walk around, come up and sit 1-2-3 times.... I don't take my signs out much anymore, but I have some for setting an occassional course.