Hi Melinda! Walt Disney World has so much to see and do that you're smart to be starting to plan for your April trip now. The Disney website has a plethora of information about each of the parks, including details on the attractions, the dining options, and a calendar of scheduled events. Here's a link to the main webpage for each of the four parks:
If you click the main links above, you'll see on the left side of each of those pages links to the calendar, attractions, restaurants, and entertainment in each park. When you're looking at the April park calendar, be sure to click the dates of your visit on the calendar -- doing so will release a pop-up schedule of parades, fireworks and other events for that day.
If you want detailed information about the parks in book form, consider buying or checking out from your library
Birnbaum's Guide to Walt Disney World. The 2012 edition is available now and contains lots of information and tips in an easy to read format.
Of course we're always happy to help here at the Moms Panel too, so don't hesitate to ask us all your questions! Wishing you a magical first Disney World vacation!