Science curriculum/book

I don't know about an illustrated curriculum, but Noeo is a literature based science curriculum. If you're just wanting to introduce your kids to science, maybe you could just skim their book lists and get the ones that will interest you. They have biology, chemistry and physics. Level 1 is supposed to be for grades 1-3, so the books they recommend would probably be age appropriate - at least for your older one. The website is http://www.noeoscience.com/

My daughter has a book called Children's Planet Earth Encyclopedia that is really cool. It's not a curriculum at all, but it's heavy on excellent, extremely interesting photographs and it covers all kinds of things related to earth science, although none of it is in great detail. It's definitely a younger kids' book. I think I only paid about $10 for it.

The book Building Foundations of Scientific Understanding is really neat if you're looking for an inexpensive program that's actually a curriculum, but it's not illustrated at all. It's on Amazon for $23, I think. It's level K-2, with 41 lessons that cover all the sciences (at a child's level, of course). I just got it and I LOVE it. It's divided into sections (biology, chemistry, etc.) that are meant to be used simultaneously. Each lesson tells you which prior lessons you need to have covered before you start and each lesson also has a list of children's books that reinforce the topic, which could be the curriculum you want with the illustrated book you want, if you just got some of the books that it recommends from the library. That's my plan.