Well yeah. WEP has been a popular choice for this purpose, but it is EXTREMELY weak if an active attacker attacks the network. But, it's a basic starting point. If you are serious about your security, don't use it.
This article describes what WEP is and links you to other alternatives. Check what is supported by your h/w.
Also, if you don't understand the security flaws described in the article, I can help you with that. There are a lot of details missing, so unless you are familar with security, it might not make much sense.