First, I want to say congrats. You'll love it at Disney!
What to bring(to the parks):
A camera
A water bottle (that way you can re-fill it. Disney has tons of water fountains, and their pop and water bottles cost a fortune)
LOTS of $$ (bleieve me, you'll need it)
a hip-pack/purse with money for pay-phones (if you don't have a cell-phone), a pen and/or pencil, and once you got them souvineers, a park map, and fastpasses.
a watch
and my brother recomends a few chains, so you can chain your valuable items to your hip pack/purse.
Do NOT take any un-necisary (sp?) items to the parks, because you will have to carry them around, and eventually, they'll get heavy.
What to bring (to Florida):
Sweats/long pants/jeans (incase it gets chilly)
Flat tennishoes (heels will get uncomforable)(sandles might make your feet exposed to chillieness)
tee shirts
shorts
sweat shirt
a watch
hair things (if your hair is long enough, it will bug the back of your neck)
a bathing suite
What time to arrive:
Arrive a little early so you can get through security (if you get there later, the lines will take you a hour)
What to ride first (Magic Kingdom):
Hit the big rides first, as they will be more popular. My family, though, goes on Dumbo first, for sentimental reasons. Then, I also highly reccomend going on not-as-big-but-almost-still-as-popular rides like Pirates Of the Carribean, and The Haunted Mansion. Pooh gets pretty long lines aswell.
What to ride first (Epcot):
Epcot only has two major rides, one of which I have never been on. I would hit Test Track first, then get a cast member to tell you about Misson:Space. I've heard about M:S, before, and since then, I have no plans to ride that ride. I heard it spins, and gets you sick to your somach. There is also a ride in the big bulby thing. I love it. My mind just blanked out and I forget what it's name is. It is a whole family ride.
Epcot is popular for The World Showcase. They have snipits of places all around the world. Norway I'm sure of has a ride. I forget what it's all about. You can get really cool pictures. Be sure to stay around for Illuminations, which is like the coolest show in Disney.
What to ride first (MGM Studios):
DEFENETLY Hit Tower of Terror first. That and Rock'n'roller coaster have un-heard of long lines after about the first 5 minutes of the park being open. Tower of Terror and R'n'R are more teen-based rides, so I sugjest that if you have younger siblings, ride it first, to see if you think they would like it.
Later in the day, I would recomend the little icecream place near TOT, called The Sunshine (I think...) It has REALLY good icecream and it's a must.
As far as shows are concerned, the most major one is called Fantasmic. It is a little scarey for younger peoples, and I think it is a waste of time. Fantasmic is basically a night time "spectacular" where all the disney villans are teaming up to destroy Mickey, and mickey has to find a way to fight back.
What to ride (Animal Kingdom)
Ask someone else. I haven't ben there in YEARS.
DownTown Disney:
Downtown Disney is an awesome place to shop and eat. If you go at night, it is cool because you can see all the lights. IMHO, don't make it a whole day thing, just go on one of the nights you have free.
Ah....the allstars...I love that place.
On the plane, I suggest that you bring a pack of hard candy. Is this your firs time fling?
I hope you have a wonderful vacation.
Feel free to P.M. me.
P.S. Make sure you get a pair of mouse ears.
Sorry for the long post, and yes, go on the Disney website, and get Birnbom's By Teens, for Teens (or By Kids, for Kids)