Wireless Configuration Problem

I'm having a problem configuring my wireless settings to be able to connect to passworded wireless networks (such as the one at my school and the one we set up at my apartment). We've been running our network without password protection for a little over a week, but we want to run it with a password so the kids above us can't steal it anymore. Basically my problem is, is that when I try and enter a password, it tells me that it has to be either 8 or 13 ascii characters in length. Also, my config options tend to differ slightly from instructions I have been given through my school. I'm not sure if I need to update my drivers, or if it's something else that needs tweaking. Anyways, I don't know what info you guys need so just ask me any questions and I can enlighten you.