Before they go back to the library:
Suburban Safari: A Year on the Lawn, by Hannah Holmes. I've been trying to get inspired about nature study even here in the concrete jungle (with a few strips of well-tended turf.) This was the book to do it, although the author's overgrown suburban backyard still sounds a lot more wild than mine. Adventures of squirrels and crows, ideas for tracking what's going on out there, incredible facts about plants and animals you thought you knew about, and quite a few laughs. She's an environmentalist, but a reasonable one who understands tradeoffs and human needs. I am inspired. Someday I, too, shall have a Freedom Lawn. (Actually, since it consists of never using chemicals or watering, mowing infrequently, and only weeding out invasive non-native plants, that's exactly what we had before, although it wasn't necessarily an environmental effort.)
The Wild Out Your Window, by Sy Montgomery. Same reason. In some spots more literary in style, but not as much fun. Full of fascinating facts. Did you know that turkey vultures mate for life, as much as sixty years? Perhaps they realize they'll never get another date.
Better than School, by Nancy Wallace. A personal account from the early days of homeschooling. I had forgotten how much we owe to those pioneers who had to explain and defend every thing they did to uncomprehending officials. Also, now I want my children to be older, so they can do cool stuff, too. Only I also want them to stay little.
The Heroes, by Charles Kingsley. Fabulous retellings of the ancient Greek myths. (Carrie, if you ever want to revisit the Ancient Greeks, this is much more cheery than the Iliad.) A bit moralizing in spots; one could hardly expect otherwise in a 19th-century father writing for his children. But oh, such fun. "It is better to die like a hero than live like an ox in a stall." Even the Bowdlerizing is scintillating: "And Daedalus fled to Crete, to Minos, and worked for him many a year, till he did a shameful deed, at which the sun hid his face on high." I can't wait until the ducklings are old enough to listen to it.
Except I want them to stay little and cute.
And a bonus one that's not from the library:
The Lost Princess, by George MacDonald. My favorite book on child discipline: though the methods are not precisely applicable (I don't have a magic room that won't produce dinner until the floor is swept), the heart of the book is. I was reminded again what an awesome job it is to have an immortal soul to guide. And I spotted a few lessons for myself, too. For the Wise Woman still has rooms to lead all of us through.