Definately rent a car, even if you are staying onsite. This will make it so you don't have to wait in long lines for busses and ride on crowded busses when you do.
There are many great on and off site hotels. Which one is the best is truly a matter of personal taste and what you require in a resort. I'd suggest either a few adjoining rooms or a villa type place since there are 3 adult couples and you'll probably want more space.
You will learn about Fastpass. This cuts down on wait times for rides a great deal. The web site
http://allearsnet.com/ goes over this a great deal.
Also, there are great places to eat and you will want to make priority seating arrangements to cut down on wait times for foods. Also, remember, you can always call and cancel them if you decide to change your mind. But it's good to have them, so you can usually go in right around the time you want.
Another great piece of advice I was given is get up early. The parks all tend to be less crowded right when they open and the animals at AK tend to be very active then.
For each park, make a list of attractions that are MUST SEES. Make sure to hit them all and then return for secondary attractions and second times on your favorites!
Do not try to do it all. You'd have to go and stay at WDW for 6 years to see and do all WDW has to offer. Read through the guides and pick out the things that are important to you.
I'd go with the middle of May, as April and early May tend to be spring breaks for kids in schools.
That site in the above post is GREAT. Also check the DISboards each day. You will find great answers to your questions!
Try not to stress too much. I think even after your kids are out on their own they will still want to go back to WDW with you! I'm 27 and live away from home with my boyfriend and I'm trying to convince my mom we need to go back! Sounds like you have a great family and I am sure they will love it! I love Disney even more now than I did as a little kid!
