A new book about the Internet of Things has been recently added to Scribd. The title says "Internet of Things. From RFID to Next-Generation Pervasive Networked Systems", and provides a good introduction to RFID-based solutions for IoT.
The only con is that it is too RFID-focused, scarcely mentioning the other side of the Internet of Things: embedded-connectivity mechanisms and protocols. In order to balance this aspect, a new book on 6LoWPAN (Amazon pre-order) "6LoWPAN: The Wireless Embedded Internet" is expected by the beginning of 2010: