Comptia Security+ certification is one of the most widely known certs in the area of computer security. The practice tests offered are from reputed vendors including Certexams.com, Transcender.com, Boson.com, and SimulationExams.com. The exam cram material is also available from several vendors. Check out the security plus section for more details.

Provides info on Cisco CCNA cert with links to relevant resources, and practice tests. CCNA, short for Cisco Certified Network Associate is a popular certification in LAN WAN technologies. Network simulators and lab simulators are available for virtual practice.