PBS
Nh Pbs: Nature Works: Communication
This comprehensive site describes how communication is an adaptation that is important for survival.
Biz Move
Biz Move: Master Your Non Verbal Communication Skills
This article dicusses many aspects of nonverbal communication - eye contact, facial expressions, distance, paralanguage, and more. This is a very good introduction to the subject.
PBS
Nh Pbs: Nature Works: Tactile Communication
Good overview of how animals communicate through tactile communication. Includes examples of different animals.