For introductory material, maybe also try the Agentinian chapter's Internet Society publication:
http://www.ipv6tf.org/pdf/ipv6forall.pdf
For advanced material, the NIST SP800-119 "guidelines for the secure deployment of IPv6" is short on advice but mind-bendingly helpful for understanding some of the more esoteric corners of the v6 protcol suite.
The biggest changes in v6 compared to v4 are that ARP is replaced by ICMPv6 neighbor discovery, that multicast ICMPv6 router advertisements are required, and there is a new DHCPv6 protocol which is controlled by flag bits in the router advertisements. Address scopes, particularly link-local versus global get a lot more prominent, since IPv6 hosts will continue using their fe80::/64 link-local addresses even after configuring 2000::/3 global scope addresses.
-- Jim Leinweber, WI State Lab of Hygiene
