advice on telling people about having the surgery

Wanted to see what advice anybody had about telling people about the surgery. Of course my best friend and family knows but that is it so far. How early should I tell the people at work I am close with? How early should I tell people I am friends with that may not have the best reaction (jealousy)? How about telling people that I know will not approve? I know people are going to ask me a zillion questions but I really dont want to be bothered before the surgery and Im sure for a while after. Its also a personal decision so I dont want all of my co-workers comming by my desk like im a zoo exibit Thanks!