Disney World consists of multiple parks--plus two water parks and other amenities such as shopping districts and golf courses--which each require at least one day to explore fully. While Disney sells Park Hopper passes that let you move from one park to another in a single day, moving between parks can be difficult since the parks are a car ride apart. Furthermore, during a peak period like the summer, crowds will be quite large, which means you might want to spend more than one day in a given park in order to see everything. Determine how much time you want to take for your Disney vacation and chart out which parks are most important to you. From there, you can prioritize each day and ensure you make the most of your stay.
Meals and hotel rooms at Disney World have a way of gobbling up your budget if you're not careful. Disney has "official" hotels on-site and sells meals inside the parks as well. If you're minding your bottom line, however, you may wish to consider other arrangements. Look into non-official hotels in Orlando--they're often less expensive than Disney hotels, though you should make sure they offer shuttle services or similar ways of getting to the parks. You should also see if they provide continental breakfasts in the morning, which will save you the cost of eating at the park.
Disney World often offers specials on park admission which can save you money if you plan right. Once you know how many days you wish to spend there, look for deals that give you extra days free if you buy a certain number of tickets or "2fer" deals which let you visit multiple parks for the price of one. Disney periodically provides discounts on plane fare or hotel fare if you use a certain airline, and other deals such as "free admission on your birthday" often crop up as well.
