I just saw your family on Fox News. We are also a homeschool family and would be glad to pass along some of my favorite places in our beautiful state.
I highly agree with the recommendations for Estes Park (mostly tourist stuff there) but mostly to go on to Rocky Mountain National Park. It is my favorite place in the whole state! Trail Ridge Road has already been mentioned, and you can drive it in your RV. If you can go all the way over to Lake Granby on the other side, GREAT (head back to Denver via I-70 from there)!! There are a lot of moose over there. Find a park ranger and they can often tell you where to look. If you can't drive, stop and turn around at Alpine Lodge. Do you have a car? If so, take Old Fall River Road up the mountain, and Trail Ridge Road back down.
Bear Lake is also another fun destination, with a short hike around the lake, and a slightly longer but easy hike to some waterfalls. There are tons of RV parks around Estes Park. Be sure to get gas in Loveland before you head up the mountain. Wait to fill up til you get a couple miles off I-25 (wave as you pass my house!)and hit the Diamond Shamrock, or the cash place next door (that now takes credit cards, but has old machines).
The restaurants in Estes Park are not very good as a whole. I've heard the Grumpy Gringo has yummy desserts, and we like eating spaghetti at Mama Rosas.
I'll disagree with the earlier recommendation for the Aquarium in Denver. There are many, many better ones across the country. We like the museums and zoos, but none are real standouts if you've traveled a lot. Instead I'd recommend you head out to Golden, which has several fascinating (and many free) museums. You might enjoy touring a gold mine as well. There are a couple in the area. We toured the Phoenix mine, and the children loved panning for gold afterward. It was in a real stream, rather than a fake trough like most places.
http://www.coloradodirectory.com/phoenixgoldmine/
Colorado Springs has a whole new batch of stuff to do. Garden of the Gods is beautiful, especially at sunset! It is hot during the day this time of year. You'd also probably enjoy the Focus on the Family campus, and perhaps checking out the Air Force Academy. I find Cave of the Winds, and Seven Falls to be extremely touristy. The Cheyenne Mountain Zoo here is a little more unique than the Denver one, and you can feed the giraffes. Denver is larger although.
Restaurants...
www.whitefencefarm.com Dinner only (the BEST fried chicken, family style, $35 for 2 adults and 2 children) and fairly near Golden and the museums there. They might have lunch on weekends. You don't need to print the coupon that is on their website. This place is a destination, even without the food!
www.cinzettis.com I-25 and 104th Ave. A wonderful and huge Italian buffet. Monday and Tuesday evenings are kids nights. Kids 12 and under are free and adults are $12.95. The prices go up on the weekends, so we only hit the kids nights ($76 on a weekend and $26 on a kids night for our family of 6).
Feel free to ask any specific questions, and I'd be glad to help! We try to see as much of our state as possible, and travel is a high priority for our family. I'd LOVE to take a year off and travel in an RV like you are doing.
I hope you are heading on to Wyoming and Yellowstone from here! We are also only 6 hour from the Black Hills.
I do love Chipotle too!

There is one by the Target in Loveland, right where you get off the interstate to head up to Rocky Mountain National Park. They do not have any kids meals.