First off, good luck!
Don't stress, although I know this is easy to say but not so easy to do.
What I'd do, would be firstly to ask my doctor what I should and shouldn't do, I mean I may want to eat a lot of things but the dotor may think it is a bad idea.
Also, remember to be prepared in terms of medications, according to your doctor's instructions. Don't take any aspirin, unless your doctor tells you to do so this particular week (which I am pretty sure he won't), for example. My friend's father used to take aspirins for his heart, and no one told him to stop prior to the heart surgery, so he kept taking them, and that made his blood thinner and he had a major bleeding during the operation. But he was OK finally, he just made it tougher for the doctors!
As for other things, I would meet with friends and go out and have a relaxed holiday-style week, but taking care of myself (not to get tired or sick). I would go to the beach, have nice food, get a relax-massage, read books, things like this. Also, I'd pray for my operation to work well.