Be informed... Ask questions, understand the procedure, the risks, the recovery time frame, the number of procedures a year your physician performs and whether or not the hospital has an orthopedic unit to manage you after surgery. Exercising as tolerated is always useful too. The stronger you are heading into surgery, the stronger you are coming out.
Conditioning. Although it is hard to exercise or lose weight if your hip hurts, any exercise is good. Either walking or swimming is an option. Doing straight leg raises and quad sets will help as well. I tell my patients to take iron supplements the month before surgery to help build up their blood count. Good luck.
Pre-surgery Info. Your physician should provide you with instructional materials or even an entire class, usually run in conjunction with the hospital where you will be having your surgery. Generally a class is most helpful the week prior to your surgery. In addition your physician may want to order physical therapy to strengthen muscles that will be important during your recovery.