This hundred-page book of five tales was written by Rowling as a fund-raiser for the Children's High Level Group, a charity that promotes children's rights.
The Tales of Beedle the Bard has been extensively reviewed in the book-blogging world, and I have nothing to add but a few short thoughts.
The stories are mildly interesting and take the form of familiar folktales from around the world. Four of the stories are new, but the final entry in the collection--"The Tale of the Three Brothers"--is a reprint of a story told in Harry Potter and the Deathly Hallows. The commentary by Dumbledore is more interesting than the tales themselves and will appeal to older Harry Potter fans.
Unfortunately, the book was not well edited (grammar and punctuation issues pop up throughout), which I found distracting. On the other hand, the drawings by Rowling herself are delightful, and Harry Potter lovers (like me!) will want this volume to complete their collection of the series.
I have not looked into the charity that will benefit from the proceeds of this book, but on the surface, it seems to be a good cause.
Published by the Children's High Level Group, 2008