Sharing files over network and Samba

[YigalB]

I have 4 XPs and one Linux FC2 connected. Now I can see the windows
machines from the Linux one - but not the other way. I know there Is
this Samba thing, and I even got into a configuration manager - but all
I could do there is change an integer variable which I had no idea what
does it do. So I didn't. 

I couldn't locate any how-to or "man smb" or "man samba" to understand
what is this Samba and how can I change the sharing attribute of certain
directories in my Linux machine.

Any idea how can I see the Linuc machine from the XPs? 

Thanks
Yigal