I had both knees done 4 years ago. Recommendation - get them both done at the same time. The reason is rehab is a real pain and there is no reason to do it twice when you can rehab both knees at the same time.
I agree with gandydancer go to a rehab clinic. Yes you can do it at home and yes it would be cheaper. If you are very self-motivated and dedicated do it home, but most of us, regardless of our self image, aren't that dedicated, myself included, and need a kick in the pants now and then. Besides the rehab gal always had some new painful exercise to do and who would want to miss that. All kidding aside you can have the best surgeon in the world and it you don't do the rehab you will not have a successful outcome.
One last point that they rarely tell you. As your knees go bad the ligaments and soft tissues do weird things to compensate for the unnatural motion of your damaged knees. The worse your knees get the more the compensation. Knee replacement fixes the bone problem, but it does nothing to return the ligaments and soft tissue back to their normal function. Therapy will fix some of it, maybe all of it, maybe not. The purpose of this paragraph is to say if you need a knee replacement do it, don't wait a couple years to get around to it.
starbits