You need to install sane and xsane. Copy the file u222v067.bin from the install cdrom to /usr/local/bin (see
http://snapscan.sourceforge.net/) then go to /etc/sane.d and open snapscan.conf and on the line firmware edit it to read;
firmware /usr/local/bin/u222v067.bin.
You need to make sure that the system is picking up usb devices. If you do xsane from the command line it should all work.
Good luck.