Christine,
it is CRAZY at Disney during spring break!! We avoid it at all costs then
You can do a descent amount of stuff if you get there when the park opens, head for a fast pass and then go on the next businest ride. When your fast pass make it to the time you can go for it, that will also be the time you can get a different fast pass. Since you have a one hour time period to use the first pass you have time to go and get a second one before using the first one which will help you to do more in less time. it will tell you on the pass when you can get another one. Do it before using the first one and you wont have so much time to wait between rides.
You will need to plan out which rides in each park are a must do for you and which ones have fast passes and go for them first . Then do what ever you can after that.
When staying on property they will have one park each day that will open one hour early that guests staying on property can do and the rest of the people have to wait until that hour is up. Sounds like a great perk!! WRONG!!!
There are thousands of people staying on property then and they will be heading for that early hour park. AVOID that park on that day or you'll be twice as crowded!!! Do a different park.
one last tip: NEVER do magic Kingdom on a saturday!! It is the busiest day of the week for it. Locals love to go on saturday.
If it will help you to plan I can get you a set of park maps next time we go and mail them to you. just let me know, it may be a few weeks since it is way too hot to go right now.
Kathy