My number one planning tip is to use a Disney Vacation Specialist. They are FREE and made our planning much less stressful. I highly recommend - Rochelle @ https://www.facebook.com/RochelleMickeyVacations.
A vacation specialist will get you a vacation quote, book your vacation, make your dining reservations, add any discounts that may become available, offer advice on anything Disney (restaurants etc) and can make changes easily to any of these things!
When to Go
The biggest decision to make is what time of year to visit Disney. Obviously you want a time that's not crowded, and not HOT. There are many websites that offer Crowd Levels per park by day. Undercover Tourist has a great online calendar. It also includes park hours and special events.
The next thing I considered is when is Free Dining offered. Each year (usually for less crowded days) Disney will offer their Dining plans for FREE. This is a great time to go! All you need to do is research what were the days that Free Dining was offered in the previous years and use that as a basis for your trip. Now the days might not be exactly the same when free dining is announced, but if you needed to tweak your check-in day in order to be within the Free Dining window, your Disney Vacation Specialist can easily do that for you. (A good site for Free Dining news is Chip & Co. He has great tips as well. )
Where to Stay
We stayed at the Pop Century Resort. This is a value priced resort. We didn't plan on spending much time in the rooms nor would we use the pools since it was December. These rooms have 2 double beds and plenty of space for 4 adults. I had talked with friends who had stayed here in the past and they recommended Pop over the other value resorts because it had it own bus, rather than sharing a bus like the All Star Resorts do.
When free dining is offered, value resorts only get the Quick Service Dining Plan for free. You can easily upgrade to the Standard Dining Plan for just a little extra a day. (Right now it's $18 per night per person.)
Disney Dining Plan
The standard dining plan includes One Snack, One Counter Service Meal and One Table Service Meal per night of your stay. You also receive a refillable mug that you can use at your resort's food court.
We are foodies, so we definitively found the Dining plan worth our money. We knew we wanted to eat at nice sit-down restaurants and enjoy ourselves. So at only $12 (the price has since increased to $18) a day we knew we would eat our monies worth. The only thing extra you will have to pay with the Dining Plan is gratuity for the table service meals.
You must make Advanced Dining Reservations (ADRs) for all your table service meals. These can be made 6 months in advance of your check-in date. I had our Disney Vacation Planner book all these for us.
How I Plan
I started planning our vacation about 7 months in advance. My family does well when everything is scheduled for a vacation. So I made a spread sheet of what parks we would be visiting on which day (based on crowd levels and extra magic hours) and then I based our ADRs on this. I knew I didn't want to waste too much time "hopping" around for our meals, so I tried to keep our ADR for the park we spent the majority of the day in, or at a resort that was close to the park we would be in. (Example: We ate dinner at Ohana (at the Polynesian Resort) the day we spent in the Magic Kingdom because it is just a boat or Monorail ride away.)
Here is my actual Disney Spreadsheet.
Planning out each day this way can help you decide if you need Park Hopping passes. It is possible to do one park per day, but we didn't want to be too rushed so we opted for 6 days with Park Hopping. This way we could always go back if we missed a parade or something that we really wanted to see.
It is also important to see what times the parades and firework shows are since these are not offered everyday. You definitively don't want to miss the Main Street Electrical Parade and Wishes Fireworks show.