no domain required. lets call the computer with the network share you are creating the server computer, and the other computer is your client. on the server computer you go to the sharing tab, share it and specify what users and/or groups have access to the share, and what permission they have (i would suggest doing it read only unless you MUST have permission to write to the drive).
on the client computer, right click on My computer on the desktop and then click on Map Network Drive. Select a drive letter, and in the folder, specify \\COMPUTERNAME\SHARENAME and then click on the "connect using a different user name" link. That will pop up a window that will ask for a username and password. Use whatever username on the server computer that you gave permission to access that share.
You may need to specify the username as COMPUTERNAME\USERNAME
I believe you could also create a user account on the server computer with the same username and password that you use on the client computer, and grant that account permissions on the server computer. By default when the client attempts to connect to the share it will use the local username/PW used on the client, so if they match whats on the server I believe that will work as well.
its been a while since Ive had to do this, but I am pretty sure its possible. I actually run a domain at home because im former windows admin geek and run my own exchange box.
if you still have problems let me know, we'll get this working, and if its porn you are trying to share across the network, you better share!