Massive Open Online Courses
Since 2010, there has been a significant boom in MOOCs (Massive Open Online Courses). These are free online courses, sometimes from the most prestigious institutions in the world, with materials, power points, and assessments. Some observers believe that they will have a drastic impact on higher education generally. At any rate, there is a lot of material out there already that may be of interest to instructors. Some examples of MOOCS:
Carnegie Mellon's Open Learning Initiative -- so far only a logic courses is available.
Coursera -- a consortium of Princeton, Penn, Stanford, and University of Michigan.
Update: 17 Dec. 2015; May 2020