Due to the high volume of recent request I decided to post this little checklist that I made for some of my customers and friends. I hope you all find it useful.
Basic Wireless Security:

Should be done:

- DO NOT use the default SSID
- DO NOT broadcast SSID
- Change the administrator Username/Password for your router
- Use WEP or WPA (if available on your router)
- Use MAC filtering if possible
- Limit the number of DHCP assigned IP address (or use static IP)
- Block ALL unassigned IP addresses
- Turn off default shares on the computer, set permissions for files that need to be shared.
- Turn off Printer sharing if it is not needed.

Optional: (not so basic)

- Limit broadcast range
- Use rotating WEPS
- When assigning IP addresses use class A or B IP’s and a class C subnet (sort of a Security through Obscurity technique against people scanning for active IP’s)
- Use a form of data encryption during transfers
- Rotate assigned IP addresses

In addition to these wireless security percussions that must be taken you must also remember to:

- Keep your operating system fully updated.
- Be sure to update your antivirus program
- Use Strong passwords (a good password should be at least 8 characters long, contain both upper and lower case letters, numbers, and special characters)
- Change your password every few months
- DO NOT use standard passwords (i.e. the same password for everything)
- Be careful what you download
- Use a program such as Ad-aware, or Spybot search & destroy to help control adware/spyware
- Use a firewall, there are many free software firewalls available.