Use the 5.x and 6.x SRND as a starting point. That's actually a good "book"...
www.cisco.com/go/srnd
Also use the Sytem Guide, Admin Guide, Feature Guide.
AFAIK there is no book available now and not coming soon (at least nothing on CiscoPress).
My experience with books: as soon as it's printed, it's old anyway... :-)
Cheers,
Martin