Before you hook this puppy up, check out this site:
Wardriving for a good overview of the security risks involved and what you can do to protect yourself.
There's lots of good stuff on securing your WiFi network.
Basically, you want to enable WEP (even though it's not 100% secure) and you want to change all the defaults so you won't fall victim to a brute force "guessing" approach when being cracked.