Hi, sorry for long delay
First, try connecting to an unencrypted AP. If that works, try enabling encryption, and monitor your logs for anything related to wlan0. Also, I don't recall what kernel version the Arch CD is using, but this being a newcommer to the linux world, you can expect night and day differences between kernel versions. You might want to find a distro with a newer kernel, or make an install from CD (and then upgrade) or via cable (ethernet).