allears.net is a huge one for me. Their information is often up-to-date and you are able to see recent reviews on hotels, restaurants, and special events from people who have been there and done that. I love the multiple reviews aspect because it gives me a good idea of continuing problems versus one time things.
easywdw.com is fantastic for crowd calendars! I also love the reviews he does because of how detailed he gets, plus he includes pictures. I also love it for tracking wait times for various rides. He also has included some great cheat sheets that I recommend to all of my first timer friends to help them with a plan of attack for each park.
disney-pal.com is a fun site, too. I don't use it for the major planning like I do the other two mentioned above, but it's a great one for me to look at leading up to the trip. It has great pictures, history, and fun facts of each restaurant, ride, and attraction in all of the parks. It helps me to get really excited and has given me ideas for little things to look at that I didn't realize were there.
