I would agree with taking the South Exit from the airport which takes you on the 417. The signs to WDW are very good getting onto the highway. There will be 2 tolls for $1 each. You can either take exit 6 or exit 3 to get to the All Stars. I believe the signs will instruct you to use Exit 3 so if you're not familiar with the area I'd do that. Taking Exit 3 will involve one additional toll for either $0.25 or $0.50 (sorry, can't remember the amount).