First up, I hope you mean touring the WDW resorts. I would avoid tours of any other resorts offered. It is not a tour, it is a timeshare presentation, and it is not a way to waste precious vacation time. If you do a timeshare presentation, just remember that most locations in Orlando (except DVC) resale for about $1 per week right now (not near the thousands they want to extract from you).
Our #1 favorite cheap day is to go the Blue Spring State Park to see the manatee (winter months). About 45 minutes North of Orlando. Park entrance is about $7 per car. The boat tour of the St John River is fascinating as well, and reasonable $ for a family. Go to the Florida State Parks web site for details.
Gatorland is a good "half-day" attraction; DS loves it, DD not so much (nothing with scaly skin interests her). DS and I also love go-karting at Funland while the girls get their shoppin' on.
We always do a day at a waterpark (usually BB or TL), and at least one visit to DisneyQuest is mandatory. Neither of these is particularly inexpensive however.
Have a great trip!