Can I suggest you use two wonderful features of the FreeNAS websites? First is the search functionality - you'll see a search box in the top right hand corner. Use it.
Second feature which will just amaze you is that, when FreeNAS was released, comprehensive documentation was written and has been constantly been developed. You'll find this here:
http://doc.freenas.org
And, just because I'm in a nice mood, you'll want to use a keyword like: MiniDLNA