IPv6 gives you more addresses.
Most books on IPv6 cover the theory.
This book is the hands-on guide to implementing IPv6.
-- Covers IETF standard (Internet Engineering Task Force) -- the official task force of the Internet.
-- Covers migration from IPv4 to IPv6.
-- Covers tunneling and IPv6 -- this provides a secure connection over the Internet.
-- Shows how to do multimedia and multicasting using IPv6.