Darren,
Welcome to the DIS! There is lots to do for all ages. We took our oldest two when they were 3 and 4 and our youngest's first trip was when she was 3. We tended to spend most of our time in Magic Kingdom. That was just us. The biggest piece of advice I can give is not to try to cram everything in or you will just exhaust everyone. In addition to the parks, enjoy your resort and enjoy other Disney experiences like riding the monorail (always a favorite), Fort Wilderness with the campfire sing along and petting zoo and Downtown Disney is also a favorite.
Planning is part of the fun...so enjoy!