i would like to setup a linux based server as a substitute for Windows 2003 Server. Could someone please tell me what version of linux i will need and any instructions on how to go about setting it up.

It will be run on a computer that is stored in the basement and will be used to hold all user files, logon details, shared resources.

the users currently have permissions (User, Power User, Admin).

the server must be able to connect to Windows XP (via lan and wan) and be able to be logged on by domain (in XP).

any help we will be great.