I consider the Foxfire series to be must-haves. Reading them is like being a kid again, listening to my grandmother, the rest of her generation, and even older relatives sitting around chatting. 
My yard is a mix of veggies, fruit, and wildlife garden. I’m even willing to battle my local clay soil to have happy Penstemon spp in the yard, and the effort pays off in native bumblebees. We also get bats in the summer (yes, this meme is totally accurate), and hunting swarms of dragonflies are a regular occurrance.
Inside the house? Field guides, local ‘best hikes’ books, gardening guides, an amazing number of books on paleontology (since neither one of us actually works in the field), and a pervasive Odonata motif. I may be a wee bit obsessed…