XSane is a graphical scanning frontend. It uses the SANE-library to talk to scanners. This means that XSane does not support any scanners itself. If you have any problems or questions that are related to your scanner then please contact the author of the sane-backend that supports your scanner or for general questions contact the SANE mailinglist. Here you can find out which scanners are supported by the SANE-library.
XSane is designed for acquiring images with scanners (there are other devices like cameras and videodevices supported by SANE, but XSane is not designed for that purpose). You can scan to file, do a photocopy, create a fax, create and send a mail and start XSane from The GIMP as gimp plug in.
If you do not know SANE please take a look here at first. For further information please read the Documentation of XSane.
It also may be interesting for you to read the report about SANE and XSane of the german computer magazin ct (year 1999 number 21 page 190).