If you're an airplane homebuilder, you should start to get in the habit of going to the EAA video tips for homebuilders before wasting a lot of time searching all over Googleland. EAA has produced hundreds of videos over the last few years and they're indexed well enough to easily find what you need.
Today, since the temperature his 30, I'm heading out to the hangar to run some antenna cable to the transponder and transponder antenna. I spent some time looking on AeroElectric Connection for a "comic book" on BNC connector installation, and I'm sure it's there somewhere but the search and navigation function on the site isn't really very good.
In some degree of desperation, I went to the EAA site. Guess what the newest video is? BNC connectors, taught by Dick Kohler, who taught the SportAir workshop on avionics that Warren Starkebaum and I went to a few years ago.
By the way, the Web site Matt's RV-7 Project, also has a good step-by-step.