$ zfs set sharesmb=name=myshare yourpool/shares/bob
You can set some text description (Windows Explorer shows this text) for the share using this:
$ zfs set "sharesmb=name=myshare,description=My ZFS share" yourpool/shares/bob
To just turn on cifs sharing for a zfs file system without specifying a share name execute a command like the following. Note that the auto-generated names created using this method are usually not user-friendly.
And then change the user's password with the "passwd" command. After this, their smb password will also be set so they can connect via smb with the same username and password.
If you want to use AD to manage your users then take a look at the following http://docs.oracle.com/cd/E19963-01/html/821-1449/manageidmutm.html#enableidmusupporttask
It allows you to enable IDMU so you can easily keep UIDs and SIDs in sync.