What model are you useing?
Have you checked out the HCL (Hardware Compatibility List) above?
I don't think there are many USB networking devices running around, so support may be limited. I haven't used it myself, but I hear some people are having success getting Windows drivers to work in linux with http://ndiswrapper.sourceforge.net
. This may not be helpful though, in that you may not be able to follow the instructions well as a newbie. (I haven't read the instructions myself, I've just heard that they involve such things as compiling, and you need to follow them closely)
Good Luck, wish I could have been more help.