You really don't want to "share a partition," period.
Rather, what you want to do is to share the drive as you do in Windows. The standard tool for doing this is called samba,
) and it allows Linux to operate as a full-featured and well-behaved Windows server.
You can gain graphical-console access to a Linux machine from a Windows machine through the use of an X-windows client
... search Google. Unlike Windows, Linux is a client-server GUI,
which means that you can get full graphical access to another machine located hundreds of miles away, without the nonsense of a terminal-server or PCAnywhere-type "solution." (sic)