"What's Wrong with Wikipedia?" is a small piece of a much meatier treatment on the Harvard Guide to Using Sources website. Beyond answering that initial question, the website provides tips to evaluating and citing credible online sources.
Educator Angela Bunyi believes it is never too early to teach kids about reliable online sources. She created four lessons that not only allow students to work on finding reliable sources when conducting research on the internet, but these lessons also teach students how to cite those sources and to avoid plagiarism.
Annenberg Classroom, a resource rich with information and lesson plans focusing specifically on civic responsibility and education, provides one such lesson plan, entitled, "The Credibility Challenge." In this lesson, students move through a series of exercises with the aim of gaining practice in determining what sources are credible.