The UND SATCA has, for some time now, been releasing a set of well-produced videos on Air Traffic Control, entitled ATcast.  These videos cover a range of approach-level (and a few tower-level) aspects of Air Traffic Control.  I've found the following episodes in particular to be very informative:

Radar Identification
Merging Target Procedures
Satellite Airports
Point Outs
ATIS
Overhead Maneuver (although I admit, the production values here aren't as good)

Obviously, these videos do not replace the in-person training that each S3-in-training must receive, but these videos may be a good way of ensuring that information is consistently communicated correctly to controllers.  They're also good for review: I can now, easily, list the six ways of radar-identifying an aircraft, when before ... I could not.

The videos are all in MP4 format, so they can be played in a browser, or downloaded for playback on your computer, and on most video-capable portable devices.  There is also a direct download link for iTunes users.