There is no one book that covers the information you're looking for - you need to research several, some of which are no longer in print although you may be able order them from your local library (or get hold of second hand copies on Ebay etc)
Genetics of The Dog - Malcolm Willis (comprehensive info on colour inheritance in dogs with separate info on Cocker colours, a little bit out of date now but still useful)
The Cocker Spaniel (English) - George Caddy (lots of photos, illustrated breed standard)
Cocker Spaniels Today - Joyce Caddy
Cocker Spaniels - Jennifer Lloyd Carey
If you do a search on this board, you'll also find quite a few threads where colour inheritance & genetics have already been discussed & links posted to websites containing further info. You'll also need to read up on the various health issues which affect Cockers - you can start by checking out the Health pages on the CSC website
HERE and the ECSCA site
HERE.
