Configuring Apple (AFP) Sharing
To share with Mac OS X computers using the default AFP protocol, click Services > AFP (see Figure 4) and mark the Enable checkbox.
Then specify the Authentication method you desire, whether you want to require users to enter a username and password (that are loaded in FreeNAS) when accessing shares with this protocol. After you're done, click Save and Restart.
Figure 4 Sharing with the default protocol
Just like the other sharing protocols, you have to click the Shares tab and specify the folders you want to share. When adding shares, at least fill in the first three fields and then you can probably use the defaults for the other settings.