Disneyland
We stayed at the Howard Johnson Motel last time we were at Disneyland and it was great. Literally over the road from the park gates and a fraction of the price of the official Disneyland hotel. http://www.hojoanaheim.com/
http://disneyland.disney.go.com/disneyland/en_US/parks/landing?name=DisneylandParkLandingPage
Hawaii
Volcanoes National Park http://www.nps.gov/havo/
Kids Go West’s recommendation for breakfast http://kidsgowest.wordpress.com/2009/04/10/wish-i-was-here-breakfast-at-dukes/
Romy’s on Oahu (shrimp shack where they grow their own shrimps) http://wanderlustandlipstick.com/blogs/wanderfood/2009/11/17/wanderfood-wednesday-romys-on-oahu-2/comment-page-1/#comment-219
Hawaiiana Live at Hilo Theatre http://holoholowale.com/2010/02/09/hawaiiana-live-at-hilos-palace-theater/
It's a small world after all 
Hi- I love what you are doing. I wish we had the opportunity to take a trip as amazing as the one you are planning. I currently live about 30 minutes from Disneyland and was born in Hawaii so I have a connection to your US destinations. I recently went to Oahu again and will be posting about some interesting and fun things to do on the island. If you make it Maui I highly reccomend watching the sunrise on Haleakala and then biking down the volcano. Maybe some of my posts about Orange County (where Disneyland is located) and Hawaii can be helpful for our trip. Happy travels!
Hello Sharlene I was looking at your post on the blog it’s a small world after all. Our family is doing a similar thing in October and will be stopping in LA for about a week and are trying to decide what to do, we would love some advice we are more lovers of space rather than cities but feel we should bite the bullet and have a look at somewhere like venice beach in LA. Places like Yosemite and Joshua tree appeal to me but I must remember the children 8 and 4, a lack of time and limited funds. Will probably hire a car other than that we are open to suggestions.
Thanks