Staying on site, you will have Disney transportation and will not need your car unless you choose to use it, or want to save time (such as going from resort to resort for dinner or going off site).
Using Disney's website, you can get package deals that include hotel and park tickets and dinning plan. You can also use a
travel agent such as Small World Vacations or
Dreams Unlimited or any number of others. Both Small World and Dreams are Disney travel agents and both are pretty good. We used Small World Vacations for our first trip and our agent (Sandy) was very helpful with suggestions and ideas.
We have never stayed off site, but there are plenty of hotels that are close to Disney that would only have you driving a few minutes to the parks. The down side of that is you will have to pay parking each day. We prefer to stay on site and use Disney transportation to get to the parks each day.
Another recommendation I would make is to get a guide book as soon as possible. You can probably find them at the local library, but they might not have the latest edition and the way things change at Disney you would do better getting the latest edition. We bought ours so that we had it to refer to when ever a question came up. There are several good ones out there, but we prefer is The Unofficial Guide to Walt Disney World 2007. It is thick and can look intimidating, but they try to cover every thing people would need to now and it has a lot of really good information. And searching these boards you can find a lot of threads that may already have answers to many of your questions. The good thing about guide books is that they answer questions you might not have known to ask.
Sorry I got so wordy, if you have other questions I'll be glad to try to help all I can.