If you don't stay in Disney resorts (they don't call it hotels), it can be cheaper. If you drive, book hotels (not Disney resorts).
There is NO resorts inside the theme parks. Look up their map and you will know that most resorts are miles away from the park. No walking distance.
Anyway, Google it and you will find tons of info on how to plan you Disney trip. My only recommendation is to book early, for instance, 6 months ahead.
If you don't want to do the homework, call an agent to book it. They don't charge you anything for booking b/c they get commission from Disney.