I am a complete newb to sharing, so bear with me in case I write something stupid!

In Windows file manager, on the file server itself, I look under Network and see the name of my computer. Under that are actually not one but two "shares" (I assume that is what they are) named "m" and "my music". Looking inside these reveals the entire tree I have shared.

On my N900 in the default file manager I have two choices: "Nokia N900" and "Shared media". Under the second is the name of my server. Under that is a list of folders: "Music", "Pictures", "Playlists", Videos". Under "Music" is a whole bunch of different ways of viewing the contents (I assume). The only file here is the one in my Public area on the server. Nothing else shows up.

Let me know if you have other questions.