You'd want to start with the Self-Study Guides that are available for the BSCI and BCMSN exams, and then move on to the Certification Guides.
For the ONT and ISCW exams you don't have any choice but to use the Exam Certificaiton Guides.
Check the CCNP FAQ for more book suggestions. If you're serious about learning (or are a closet CCIE hopeful) follow the suggestions about also using some of the CCIE books too.
And at the Professional Level you should get comfortable using the Cisco Documentation (some links are in the FAQ to get you started).
are you gonna go for ccie?