This screencast introduces comparison and contrast transition words and provides examples of how to incorporate them in sentences.
Source: Kathryn Reilly
For more help with comparison and contrast transition words, try the following websites:
http://urbandreams.ousd.k12.ca.us/lessonplans/extended/9/garland/docs/Compare_Contrast_Intro.pdf
http://writing2.richmond.edu/writing/wweb/trans1.html
http://www.readwritethink.org/files/resources/interactives/compcontrast/
Source: see above