Yeah you can - both ways round in fact. I've got FC4 installed and I'm able to share file between my work laptop (Windows XP) and my home PC (FC4) in both directions. To do so, make sure you've got samba enabled on your Linux machine. To set up shares, users etc on your Linux machine, run
which will ask you for the root password before you can proceed. Unfortunately it seems that samba users are a completely separate thing to linux users, so you'll have to set any user(s) you want up in the samba config program, or enable the guest account. You'll also want to set the workgroup to the same name as your domain, and enable netbios name resolution on linux; I can't remember if you can do this through the system-config-samba
app but if you can't then you can do it in /etc/samba/smb.conf
I think you can even make Linux authenticate against your DC if you try hard enough - somewhere in the authentication settings (system-config-something, i can't remember the exact name), there's an option to authenticate against LDAP - just point this at your DC and it should work). I haven't ever tried that though so that's about as far as my knowledge goes.