Hi Tara!
We are studying insects right now. One of the books we have really benefitted from in our study is the book Entomology by Ellen Doris. (It’s recommended for ages 9-12, but I think it’s really for younger children than that.) The book intersperses “chapters” – 2-page spreads – about the actual science of entomology (taxonomy, methods, etc.) with “field trips”- places to go to find different bugs and how to keep them alive for observation. It is a simple book, but has been very helpful to us.
We are also reading SCM’s “Jack’s Insects” and have loved it so far!
Happy bug hunting! I know we’re loving it! (OK, well, at least the children are…I’m not such a big fan of bugs myself…) 
~Anna