Bree Tanner was one of the newborn vampires in Eclipse (the only one mentioned by name in the book), and Stephenie Meyer wrote a short (192 pages) book about her. It is being released today, and is available in Kindle format. The book is told from Bree's point of view, and some of the plot points are included in the Eclipse movie, to be released June 30. Apparently the book shows another side of some of the events in Eclipse.
$1 from every hardcover sold in the US from the first printing goes to the American Red Cross.
http://breetanner.com/Amazon is selling the Kindle version for $9.99, and the hardcover for $6.99. (I'll never understand this, and I'm really not happy about it.)
Stephenie Meyer is making the book available for fans to read on her website for free, beginning Monday, June 7 at noon.
http://www.stepheniemeyer.com/index.html