Searching online is an important and often overlooked skill for students, and teachers, to learn.
This resource from Free Technology for Teachers is a useful guide to help anyone learn to search effectively.
http://www.freetech4teachers.com/2015/06/10-important-google-search-strategies.html#.VYl0UxNViko
This is some of the same information but in a catchy, infographic format.
http://www.freetech4teachers.com/2014/08/great-google-search-strategies-every.html#.VYmGNhNViko