Lots of times I like to read what I call "list" books: books which contain short articles, sometimes only a paragraph or two, about a topic. Stuff you can read, put down, and pick up again without losing a beat because the next paragraph is about something completely different. Here are some titles:

Saints preserve us! (a rather irreverent hagiography)

Who in hell? (similar to the above, by the same authors, but great                sinners instead)

Stories in Stone (a book of epitaths)

Various cartoon collections: Bill Watterson, Darby Conley, Bill mend, Allen Magruder, Frank Cho, Jerry Scott, Jim Borgman, Mike Peters, Berk Breathed, Gary Larson, Doug Marlette, and so on.

Unwritten laws.

100 Ways To Die In the Outdoors.

Pat McManus's books -- The Night The Bear Ate Gumbaw, The Bear In The Attic, How I Got This Way, Real Ponies Don't Go Oink!, and lots of others. (Warning: they are FUNNY!!)