I stayed at Williston Crossings RV Resort last winter. It's in the small town of Williston and is about 15 miles SW of Gainesville. It is just about the nicest park I've ever been in. It's huge - about 5-600 sites and because of that they have all sorts of activities going on all the time during the winter.
Take a look at their site because the rates vary depending on the length of stay.
If you are interested then I would advise you very strongly to call and make a reservation ASAP as they do fill up for the winter. They are a Good Sam's 10/10/10 rated park.
You can PM me if you have questions.
Tim