Multi-valued logics

Giovanni Panti (University of Udine Department of Mathematics and Computer Science) wrote a nice survey of the subject for the Handbook of Defensible Reasoning and Uncertainty Management Systems (D. Gabbay and P. Smets eds., Kluwer, 25-74, 1998). It's available via his papers' page:
Giovanni Panti : Multi-valued logics (General survey. Some material on the proof theoretic side is included).

Added (July 2006):
Sigfried Gottwald : Many-Valued Logics (General survey with special emphasis on t-norms and fuzzy logic. Algebraic-semantic point of view).

[For more on the the proof-theoretic side, have a look at Richard Zach's papers on the subject ( available on his publications page), and papers of Arnon Avron.]


Added (July 2006):
Walter Carnielli : Many-valued Models (32 p.)
[Contrary to the above papers, this one gives many-valued methods for independance results, and also has interest in paraconsistant logics.
It is one of the tutorials offered at the 1st World Congress and School on Universal Logic (2005) ]