Computer networking first-step
Networking Basics CCNA 1 Companion Guide
Routers and Routing Basics CCNA 2 Companion Guide
CCNA Video Mentor; more than two hours of personal, visual instruction on CCNA configuration tasks
CCNA ICND2 Official Exam Certification Guide, 2e
CCENT/CCNA ICND1Official Exam Certification Guide, 2e
Computer Networking First-Step