Fiction by Jonathan Tropper.
This book was similar to This is Where I Leave You, which I read recently by the same author. I think I would have liked it better if I hadn't been comparing it to the other one. Both novels were about a not-very-likable man going back to his estranged family in the town where he'd been raised because of an ill-or-dead parent.
Both had a good story, but This is Where I Leave You was way funnier. The Book of Joe was probably better-written, but I couldn't enjoy reading about a guy I didn't like if he wasn't all that funny.