Physical Preparation

In no particular order:

Make sure you are comfortable with your surgeons and trust them. If you need to get second and third opinions, do it.

One of the things that helped me deal with my fear when facing a 10-12 hour-long surgery was listening to "Preparing for Surgery" by Martin Rossman MD every day for at least 2 weeks prior to my surgery.... and then for several weeks afterwards:
http://www.thehealingmind.org/products/index.php?main_page=product_info&products_id=11

Another was learning everything I could possibly learn--what to expect, how to prepare for what I'd need at home for my recovery, etc--from my doctors and also from patients who had undergone this type of surgery. My surgeon put me in touch with a couple of his patients and that was very helpful.

Physically, you would need to consult with your doctor so that you get an answer tailored to your particular situation.

Bottom line, make lists of questions and don't be afraid to ask them.

Best of luck to you! Preparing for any type of surgery, let alone a surgery that will alter your physical appearance can be overwhelming. You did not mention the type of surgery you will be having, so I am not sure if my answer will be appropriate for you. I had a double mastectomy with tissue expanders. My preparation was simplistic. Picking the right surgeons was of prime importance to me. Once this was done, I communicated to them my anxiety about waking up having a part of me….. for lack of a better word, amputated. I needed to understand exactly what they were going to be doing, and how I would look and feel after the surgery. Fortunately, with a sense of confidence, they were able to explain in detail how the procedures were going to be done which gave me inner strength to put my faith in them. Don’t be afraid to ask questions. I feel nothing is going to take away the thoughts of fear, but I tried to think of the surgery as a positive, not a negative---the cancer was being TAKEN from my body, and in its place, I would have new and improved parts. Perhaps an odd way to think about surgery, but it worked for me. I am a physically fit person already, so recovery was rather easy for me. I did however, ask the doctors what type of exercises they suggest after the surgery. I made sure that I practiced them before the surgery, so I was better able to do them after the surgery. I do wish you all the best for your surgery and a speedy recovery!