Writer's block is a tough one to deal with. For me, I'm usually working on at least three books at the same time. Okay, maybe not at the same time, but I've got three in the works at any given time. This helps because when I get stuck on one book/character/scene, etc, I can usually venture over to another and pick right back up. Sometimes that spurs inspiration for the other project and I dive right back in.
Then there are times when you can do nothing but step away from it altogether and read.