I might suggest you look into using Fourth on AVR. I don't have experience with it myself, but I've watched quite a few tutorials and played around with arduino's on a few occasions. There's this newer guy on YouTube doing electronics tutorials using Fourth and it looks interesting.
https://youtu.be/EnCyPzSsloo. All the books I have pretty much require you to do a bunch of boring projects, but that's the typical junk you find at the local bookstores.
I would NOT recommend:
Arduino Workshop (Boxall)
Arduino Robot Bonanza (McComb)
These are what the local Barns and Noble had in stock at one point and I bought.
Programming Arduino Getting Started With Sketches (Monk)
That's a very small reference that is more direct, but it is very very basic.
From what I've seen, Adafruit/Sparkfun/Arduino Forum/YT have a reference for almost anything you could ever need IMHO.