The digital broadcast transition completed in June 2009, and your teenage son just brought home a straight-A report card. Time to purchase that converter box and dust off the old TV sitting in the garage to set up in his room per your agreement.
Screw the TV antenna into the "Antenna In" jack on the digital converter box using the basic coax cable (screw in type). If you have an outdoor antenna, the coax cable connection should be running through your wall.
Connect the digital converter box to your TV. Using either coax cable again or RCA cables, connect the cable to the video/audio "Out" jacks on the digital converter box into the video/audio "In" jacks on the TV.
Set the TV to either the AV (also might be called input, TV/Video or device) setting that you connected into if you connected with the RCA cables, or channel 3 or 4 if you connected via coax cable.