Here are some excellent sources of information on that topic.
Thank you for using the Jiskha Homework Help Forum. First of, what is it? Once you understand that you will see the WHY and HOW:
2. (identifying targets): http://www.criticalthinking.org/articles/ct-identifying-targets.cfm
3. (PDF file to download): www.educause.edu/ir/library/pdf/EQM0048.pdf
5. (introduction to critical thinking): http://www.freeinquiry.com/critical-thinking.html
6. (some lessons in how to teach critical thinking): (PDF file):