Yes, I'd say start with a guidebook - something with photos, so you get visuals of what the things are...I like the Birnbaum guide. Passporter guidebooks also have photos and a LOT of info but are a fairly easy read. Also the "Walt Disney World 2013 With Kids" is very good - no pics, though.
Second, study these boards! If you have a question, start with a "search" because everyone's already asked pretty much everything - your answer is likely on here already.
Third, include the whole family in the planning and let them pick about 3 "must-do" activities for the day, no matter where you end up. Definitely bring a lot of money on your trip and a good attitude. Take rest breaks. Get in shape beforehand, wear comfy shoes and hydrate.