I think the best utility to use is wicd-curses for wifi. It supports graceful eth0 (wired) handover and you can setup multiple Access Points with ease.
If you don't have it do the 'ol
$ sudo apt-get install wicd-curses to install it.
Next make sure your wifi adapter has been detected using
$ dmesg (it should be listed in there if it's supported)
Then if it's there, run
$ wicd-curses to set up your wifi networks. Much easier for a first timer than using wpa_supplicant and the necessary config files.
![Wink ;)](./images/smilies/icon_e_wink.gif)