Kristine – I could have written your words – I too find it hard to find non fiction that the girls will enjoy, although through Nonfiction Monday I’ve found some good suggestions that have worked. At the moment we’re enjoying “Poo” (yep, that sort) – which was reviewed here:
http://missrumphiuseffect.blogspot.com/2010/01/nonfiction-monday-davies-and-layton.html (Called “Poop” in the US edition)

I’m glad you share your non-fiction books. I must say I find it challenging to find good non-fiction for little kids. It’s either too simple or the language and vocabulary are to complex. We’ve borrowed some dinosaur books recently and I’m finding that it works best for us just to flip through until my daughter finds a picture that grabs her interest and then we just talk and talk and talk about what we see, our hypothesis and wonders.

Another book along this line is the Charlie and Lola “I’m inventing a usefulish invention”

An online invention fair would be really good….