Ok, well since I am in the same situation and am taking my DS (6) in June, maybe some of what I learned will help you. First of all I have been saving a little money for a couple of years and then some big money since Jan. We are staying for nine whole days and have two days with travel.
1. Plan early and around some specials. My tickets from Omaha NE going down to Orlando I got for $59.00. Coming back were more expensive but even going down that is fabulous.
2. Look at renting points. I am staying at OKW from Sun-Thurs for a little more than what I paying at POP for the rest of the nights. I would have booked more at OKW, but only want to move once. Plus get some nice extras like being able to pool hop when we are OKW. We will definitely get to swim at some of the other pools, esp the themed ones that interest my son.
3. See if you can share your vacation with people. My son and I are there for half the time by ourselves, and then my friend and her daughter are sharing a room with us for the last half.
4. Sign up for the Mousesavers newsletter. They offer some discounts for tickets that are cheaper than anywhere else.
5. Dont rent a car unless you have to. We are only getting one the very last day because we want to go to the ocean.
6. Have groceries delivered. We are going to use wegoshop and for $15.00 they will deliver $100 worth of groceries and will go to Wal-Mart for me.
7. `Look at all you want to do and read, read, read. I figured out that it was completely worth it to add on the Magic Plus as it was almost what I would pay to do one water park. Plus now we can do two water parks and Disney quest.
8. Figure out how much you eat. The MYW Dining Plan sounds great, but I lost 100 lbs and dont want to gain it back. When considering the plan I found myself revolving my day around food. Decide what is most important.
9. I joined
AAA for the discount on POP. It cost me the same amount of money to join as if I would have had to pay the rack rate for 4 nights. Plus now I have a one year protection.
10. We are planning on doing early dinners to hopefully catch the end of Lunch prices for our big meal and then have a late snack if hungry.
11. Check out allearsnet.com. Lots of information.
12. Check these boards often, they always have great ideas.
Good luck. I am so excited for our trip, we leave in 14 days.

My son still has no idea. I just know that once I get back I am going to have to start planning the next one and looking for more deals.
Thanks for everyones help!!!!!!!!