Troubleshooting
No Internet Access
Intermittent Cable/DSL Connection Using a Router
Forgotten or Lost Router Password

Security
Guide to Internet Security
Wireless Security: Preventing Unauthorized Access
How are a Computer's Ports Secured?
How is Port Forwarding Configured?
Security: Comparing NAT, Static Content Filtering, SPI, and Firewalls

Other Useful Documents
ISP Configuration Guide
Internet Games and Applications with NETGEAR Routers
Why Do I Need a Router When I Already Have an Internet Connection?