Hi there Amy!
Congratulations on deciding to visit Walt Disney World! My favorite time of year for the toddler and pre-school crowd is after Labor Day, when schools are back in session. The parks are MUCH less crowded than during peak summer vacation months, and the weather is still very warm, enabling guests to make full use of their resort pools and the water parks (both of which have amazing areas for little children). I visited when my son was one the week after Labor Day, and we enjoyed some of the smallest crowds to date. We almost walked onto a number of very popular rides. He also loved Tikes Peak at Blizzard Beach, which is a wonderfully-themed area just for little guys!
Currently, Disney is offering a number of specials and promotions for guests travelling through August 15th, including a Buy Four, Get Three Free promotion. While there is no word at this time for specials that may be extended (or new ones) for the Fall, I recommend continuing to check
www.disneyworld.com for promotions that cover your travel period. In the past, Disney has offered some great deals for the period beginning late August into the Fall.
Have a great time planning!
Tanya