I teach a general education Humanities course on visual literacy and use
Deborah Curtiss's INTRODUCTION TO VISUAL LITERACY (which is now out of
print) and John Berger's WAYS OF SEEING (a little bit dated now, but still
one of the most concise and trenchent analyses of issues in looking at
images).
 
Good introductory texts in different fields might be useful--I use
Bordwell and Thompson's FILM ART: AN INTRODUCTION in my Intro. to Film
classes, but social and semiotic elements are dealt with somewhat more by
Sobchack and Sobchack as well as Bruce Kawin's HOW MOVIES WORK.
 
A very interesting book is UNDERSTANDING COMICS by Scott McDougal (I can't
swear I have the title and author right but I'll check on it if you want.
It's published by Kitchen Sink Press.)
 
CHANNELS OF DISCOURSE is a good anthology of articles about tv (ed. Robert
Allen).
 
--Don Larsson, Mankato State U., MN