Plan to spend plenty time at the swimming pool at DC it is the best thing about it!
Don't forget that there is a big Auchan hypermarket close by to get stuff from and outlets designer shops at La Vallee about 10 mins drive away from DC.
The restaurant at DC isn't great TBH. We ate at the parks or in the Disney Village with the children before we left for the day at around 5pm ish and then bought plenty cheese bread and red wine for DH and I to snack on in the evening once the children were in bed.
The breakfasts are very nice at DC - croissants fresh baguette nutella, butter and jam which you collect from the little hut at the end of your culdesac.
Try to book a character breakfast. The one in the Disney Village are very busy but you can book the hotel ones which are much better value - the Disneyland hotel one is the best IME! You get much more character time per child at the hotel ones.
The food in the parks is quite expensive and not great quality - so try and plan round this if you can. Queues at lunchtimes are horrific so try and eat earlier or later and then get on some of the rides while everyone else is having lunch.
Make sure you pick up fast passes for the popular rides such as Peter Pan (your age group will love this)! Also the children love its a small small world and the queues for this move very quickly.
IIRC there is a water park bit over near the little mermaid which will let them cool off if it is a hot day (I may be getting mixed up with Florida here)!
As others have said the parades and character sites are much less busy in the Studios so make sure you spend some time there if you can
Hope you have a wonderful time!!