Help prevent your IP address from getting blacklisted or blocked by:
Implement a hardware and/or software based firewall solution.
Install an anti-virus software product. (WARNING: some viruses and worms can disable your anti-virus and firewall software without your knowledge. In these situations, you will want to fully uninstall, and then reinstall anti-virus and firewall software. If this fails to remedy the problem, the infected machine will need to be reformatted and reimaged).
Update virus definitions on a regular basis (Recommended: daily)
Run a full virus scan on all systems frequently (Recommended: daily)
Disable all unnecessary services including: file/print sharing, Web/FTP/email/DNS servers, and remote access services. Consider blocking the following ports both egress and ingress: 135 tcp, 139 tcp, 445 tcp, 1025 tcp, 1433 tcp, 2745 tcp, 5000 tcp, 137 udp, and 1434 udp.
Consider installing an anti-spyware and/or anti-trojan software solution.
To help counteract recent worms such as the Storm worm, block incoming port 80 tcp requests to all IPs other than your webserver(s).
To counter email worms, block egress port 25 tcp traffic to all destinations other than the authorized SMTP server at the router or firewall and monitor your logs for any machines attempting to violate this rule set.
Wireless routers should be password protected, using WPA or WPA2 encryption (WEP only if WPA is not available), MAC address filter enabled, and SSID broadcast disabled.
Remember to always mark items that you find useful as "Accepted Solutions". This will help other users find this information too!!