FreeNAS for LAN-based cloud

It has been interesting learning to use Google Classroom and the benefits of Google Drive.  The  flash drives have been eliminated and media workflows have been improved.  However, I want a network drive to store media assets with read-only permissions and another drive where users have read/write permissions for rapid collaboration.

Therefore, I am looking at freeNAS software to help me create these 2 network drives.  Everything is going well so far.  My rig features a desktop with Asus M3A78-CM mobo with 8 GB RAM, 3 @ 80gb sata drives and FreeNAS 9.3.   However, still trying to figure out how to set permission on Windows CIFS share drive.