Slow and steady so you don't do more damage!..
Here is a good example of the exercises you can do...
Type the following webb address into your browser [or cut & paste]... http://www.orthoinfo.org/booklet/view_exercise.cfm?Thread_ID=18&topcategory=Spine
Speaking from personal experience as a physician who has this disorder for many years now, I have found the best therapy is stretching similar to what you would do before participation in a football game, baseball game, or track meet. Swimming can be beneficial if you do not have facet arthritits, if so any repetitive exercise can aggrevate it. Also bicycling can be good but with the same restrictions as with swimming. Avoid running or anything that causes pounding of the spine. Yoga on a very limited or low level can help, but many of the positions are impossible for someone with spinal problems. I have also found that stress is a major factor in pain control for this disease, I discovered this accidentally after years of marital problems. After my divorce, my pain was much more tolerable. Some people get relief by using Glucosamine/Chondroitin, but be patient, it takes several weeks for it to work. Feel free to contact me if you have any other questions.