I installed samba4 in Ubuntu 10.04 and am having problems due to syntax differences. I can not find documentation to get this to work anywhere on the web. All I can find it stuff for older version of Samba so that's what I plan to use.
Version 4 is listed as "alpha-ware" and unless you're a developer and / or willing to put up with the associated problems of potential bugs then version 3 should work much better.
To revert back to version 3 you could use the Synaptic package manager to remove the package(s) you added for version 4. Be sure you get the "meta-package", not just the pieces. Then pick version 3 meta-package and add it.
Next you'll have to modify the smb.conf file to add your shares explicitly. User home directories are often shared by the default smb.conf but YMMV.
Assuming you want to restrict access, you'll have to add passwords for users, usually with smbpasswd -a username
Then start up the smbd -D and nmbd -D (D means run as daemons) and you should be up and running. smbcontrol can also be used to kick things off or shut down