I'm laggardly with the book posts, but I am reading, and surprising myself with all the ways to tuck in a few pages throughout the day.
For the first Read 52 Books in 52 Weeks I dug Discover Nature in Winter: Things to Know and Things to Do (Discover Nature , No 6) out of our winter reading basket.
Discover Nature in Winter is more than just a nature guide; it's a "discover and do" guide full of lessons about winter (what causes it?) and creature/plant life (what happens to them?) and suggestions for activities to explore winter. I particularly like the winter tree/weed identification sections, insect life, and the night sky. Those are areas I'll delve into with my children during our nature study times.
I own several of Elizabeth P. Lawlor's nature discovery books and consider them to be among the best of our nature study resources.