6LoWPAN: The Wireless Embedded Internet

This book, by Zach Shelby and Carsten Bormann, gives the complete picture of 6LoWPAN technology in one place, including deployment examples and implementation aspects. It is aimed at experts in the field, engineering students and lecturers. An accompanying web-site is available including course material, Contiki coding exercises, an author blog and other 6LoWPAN information.

More info here and here.