Be sure to check out the web's oldest dedicated FPV video forum.
https://www.rc-cam.com/forum/
The rc-cam forum has interesting technical discussions with a long history in the FPV hobby starting in the late 1990's. It should be noted that the rc-cam forum members created this fantastic hobby and they are the ones that named it FPV!
Edit Aug 2021: The rc-cam.com forum has permanently shutdown.