I just finished taking the ED-104 course on Classroom Management Strategies.  Although I've been teaching for over 20 years, there were a number of valuable lessons learned in this course.  I particularly enjoyed the brief, but poignant video bits from Harvard instructors.  The class deals with obvious issues-New Instructor Anxieties, Tuned out Students, Cheating, etc.  But if you take the time to really read each segment thoroughly, there are some helpful solutions.  I was especially struck by the advice that "all ambiguous communication" is perceived as "negative communication."  It reminded me how important it is to be clear and not leave any presumption to chance.