Hello OP....I wanted to broach a few thoughts for you to mull over. (in the interest of full disclosure, as a frequent traveler to Las Vegas, I do not endorse it as a kid friendly destination)
The "hawkers" are still out on the street shoving "adult" entertainment (think girlie/escort) options in your hand. It's better than it used to be, but they're still there. Be prepared to run interference for your DS and to expect questions
Gone are the days of the .99 shrimp cocktail and the 1.99 steak. Food can be pricey--especially in the hotels.
The strip is LONG........there's maps online showing where each casino is. I'd pick one centrally located (not downtown). There is a tram that connects some of the hotels but it's easy to grab a cab at any hotel cab stand. I didn't catch
when you're going but summer is brutal---hot and dry.
Consider a trip to the Hoover Dam---it's absolutely fascinating. (I'm one of those people who love knowing how/why things work)
My personal favorite hotel is the Palazzo or Venentian. The Luxor is fun--be sure to ask for a room in the main building. It was getting a tad worn last time I was there.
Check out the indoor fountains at Caesar's---they come to "life" periodically.
Enjoy your planning.