A Mac filter is not false security. It is not 100% secure but no security is. It is just part of the total security system and is worth doing as it will deter all but the most determined hackers, along with the other security features of course.
Link which tells you how to get your MAC addresses:
http://www.wikihow.com/Find-the-MAC-...-Your-Computer
link which tells you how to set up your router for MAC filtering and other security measures:
http://www1.linksys.com/support/trou...filtering.html
If you have any problems let me know.