Bet you can't read just one
There are so many interesting and informative blogs out there. One way to find blogs that you want to read is through the blogs you already read. Many blogs include a list of recommended sites along the side (see our blogroll over there on the right), and often you'll find bloggers mentioning each other in their posts.
For example, I like to look at Book By Its Cover, a blog that celebrates the art of all kinds of books, including picture books, graphic novels, and handmade books.
And speaking of beautiful books, you can view a slide show of The New York Times Best Illustrated Children's Books 2007.