Hi Antony and welcome to the Mom's Panel!
How exciting that you are a planning a trip to Walt Disney World in August - it will be here before you know it. You don't say in your question how many days that you will be visiting for or the ages of your family but assuming that you have sufficient days, I would plan on spending one full day at each of the four theme parks and two water parks to start with. If this leaves you with spare days, I would then recommend spending an additional day at Magic Kingdom & Epcot.
It can seem daunting planning a trip of this magnitude and my best advice would be to break it all down. Start by planning which parks you will visit each day and check the
Park Hours in advance of your visit so that you are prepared. Then have a look at the attractions at each park and decide which ones are must-dos during the day of your visit.
Have you thought about making any dining reservations? I would highly recommend attending at least one
character meal during your trip as they are a lot of fun for all of the family. Advanced dining reservations can be made online at the Walt Disney World website
HERE
I hope that this information has been of help and would be more than happy to assist you further should you have any more questions.
Wishing you a magical holiday filled with memories that will last a lifetime!