I've got a family of Disney fanatics. We're down there 1-2 times a year. So I can help you out.
The best piece of advice I can give you is to pick up
The Official Guide To Walt Disney World 2012 by Bob Sehlinger & Len Testa. This is considered the bible by Disney vacationers. It's about $12 at Amazon. When you're spending hundreds of dollars on a trip, a good guide book is the best investment you can make.
When planning your vacation, check out the Crowd Calendar at
TouringPlans. Try to pick a week when the crowds will be light. This site is run by the same guys what write the Unofficial Guide book.
Probably the best time of year is the last two weeks of January. Crowd levels are at their lowest point. Hotel rates are cheapest. And the weather is nice and cool, although last year it was really cold.
I would never buy tickets at a gas station or roadside vender. You run a big risk of getting screwed. There are legitimate discounts for Military, AAA and a few other groups. Check out
Mousesavers for more info.
I don't recommend the Disney Dining Plan unless it's free. Sometimes they'll give you
Free Dining with a Hotel + Tickets package. But you're really limited with the Dining Plan. It only works at certain restaurants and for certain items on the menu. And the Kids Menu choices are extremely limited.
When booking your hotel, never pay the full rate you see at the WDW website. Check out
Mousesavers. They have Discount Codes that can save you 25%-40%. And even after you book the hotel, keep checking the site for new codes. You can call Disney Reservations and change the discount.
If anyone in your group is Military (active or retired) or DOD employees, stay at
Shades Of Green. It's a prime location right in the middle of Disney World. Cheap rooms and cheap tickets.
If you want to eat at sit-down restaurants or Character Meal restaurants, you have to make reservations ASAP. The most popular places are booked 6 months in advance.
If you have young kids, don't go non-stop. Get to the park at opening and stay until lunch. Then head back to your hotel and take a nap, play in the pool. Head back to the parks for dinner, parade and fireworks.
I really like the Park Hopper passes. Especially if you're going back to the hotel mid-day for a rest. Then at night you can go to a different park. Don't buy the Water Park & More tickets unless you're going to the waterparks.
If you plan to use the hotel buses, then stay at one of the official Disney hotels. The off-site hotels have awful bus schedules. The Disney buses are much better.
If you're driving yourself and you want to stay off-site, consider a vacation home. Check out
All Star Vacation Homes. Lots of great locations within 5 minutes of WDW. Cheaper than many hotels, better amenities, private pool, etc.
If you have little girls, make a reservation at the
Bibbidi Bobbidi Boutique.
You can do some additional research at these Disney sites:
Mousesavers - The best site for Disney travel discounts
DISboards - The biggest Disney fanatic forum. The best place to ask questions and get advice from experienced WDW vacationers.
AllEars.Net - A great site for Disney Park info. Hotel Pics & Reviews. Restaurant Menus.
Mouse Planet - Weekly resort updates that list Scheduled Refurbishments, Ride Closures and other useful info.