Hmmm.... where to start, where to start.
Well, first thing is that you do have some time to plan, and you won't be going at an extremely busy time, which is great.
You really need to decide what type of park ticket you're interested in before really planning things park-wise. If you go with a park-hopper, then you can go from park to park to park all in one day. If you choose to go without the hopper, then your limited to one park per day.
Dining-wise, if you stay on Disney property, you can book reservations up to 6 months (180 Days) of your arrival date. You're looking at being able to book your dining reservations some time in March. It's important that you do this as soon as you can in order to guarantee you get what you want. There are A LOT of different dining options and that includes many, many character dinings.
If I were you, I would purchase "Birmbaum's Guide to Walt Disney World 2010"
It's a great book that breaks down each and every section of Walt Dsney World, including a review of every single restaurant and even a rating of the best restaurants. Read this book cover to cover (maybe even a few times). As big as Disney is, you won't be able to cover everything, even in a week's time, so plan for the things that you definitely want to do. Don't be surprised if, when you return home, you begin planning your next trip. Disney World is addictive... it's magical...
I'm a 23 year old male from Virginia who when for the first time at age 21... I've been back 4 times since, and am going again in January.
If there is anything I can do, please let me know.