Hi, and Welcome to the Great American Roadtrip Forum.

With your three children it will be essential to know where the parks are along the way, even if only to let them run around and let off steam.

Here is a thread which will help with choosing what you are looking for. You will find that all good maps have most of these; and maybe more, marked on them.

I'll leave the rest up to others who are perhaps more familiar with the area.

Lifey