How to stream movies from world book? I have a mac and apple TV on network

I just installed a new world book II on my network.  I’m a bit of a dummy with network drives.  I have a terabyte of movies and tv shows that I’ll put on the drive.

What’s the best way to manage movies and be able to stream them to my TV?  I don’t know what folder to keep them in, what to use to stream (itunes or the built in twonky stuff), etc.

Currently I keep the movies in .mp4 format on an external- to play, I hook up the drive, drag it to my itunes and stream to the apple tv.

How can I do this wirelessly?

I should also add that I have a Sony PS3, not sure if that can act as a media streamer either.