Karen,
My general recommendation is to allow 2 days each for touring the Magic Kingdom and Epcot, and 1 day each for Hollywood Studios and Animal Kingdom. If you have more time available you can certainly fill it as well!
As for skipping Animal Kingdom...that hurts my heart a little! I adore the Animal Kingdom, and it is my family's second favorite park (behind the perennial favorite Magic Kingdom). It's really an often overlooked star in the Disney crown, and I would never advise skipping it. No Kilimanjaro Safaris? No Expedition Everest? No Festival of the Lion King, or Finding Nemo The Musical? Ack! It just wouldn't be Disney without them. There are a lot of wonderful rides, shows and experiences in this park, not to mention my favorite parade in all of Disney World. It's definitely not a zoo! I'd put Animal Kingdom on my must-see list. :)
Also on my must-see list:
- Space Mountain
- Buzz Lightyear
- It's A Small World
- Wishes fireworks
- Lights, Motors, Action! Extreme Stunt Show
- Rock N Rollercoaster
- Spaceship Earth
- Soarin'
- Festival of the Lion King show
- Kilimanjaro Safaris
- Expedition Everest
- Jammin' Jungle parade
For dining, I highly recommend Chef Mickey's, O'Hana dinner, Flame Tree BBQ, Cosmic Ray's Starlight Cafe, Le Cellier, Beaches N Cream, and Whispering Canyon Cafe (to name a few favorites from each category)
I hope this helps you with you planning!