The book of the Sisterhood of the Traveling Pants was written by Ann Brashares. This book is one of the best books I have ever read. It's the kind of book you get hooked on just by reading the first page.
The book talks about four best friends, Carmen, Tibby, Lena and Bridget. These girls are preparing to split up for the summer. Carmen finds a pair of jeans at a thrift shop and buys them for $3.49. The four girls try them on and realize even though they each have different body shapes, the pants fit them all perfectly. They realize these pants are special or magic. They promise to keep in touch during the summer and decide to have the pants travel between one another to keep them in touch with each other. They decide none of them can keep the pants for more than one week. They even make rules for the pants and that's the story of the traveling pants.