Dont do Disney in June/July/August. You will melt standing in line. If you absolutely must go to Disney in the Summer I have a couple of recommendations.
a) Stay on the Disney property if you can. If you do you get access to what they call the Extra Magic Hrs. Basically you get access to the park one hr early and they are also doing it this year where they also run certain parks for three hrs after closing. Only people staying on a Disney hotel get access. What this translates to is no waiting times, just open ques everywhere. Here is a link with more info and times:
http://www.allearsnet.com/tp/emhour.htm
b) Do the parks early in the day or at night only. Use the daytime hrs when its sweltering hot to sit by the pool or shop in AC.