Authority is constructed and contextual. Check the AUTHORITY of your sources - make sure they know what they are talking/writing about.
Information has value. Yes, there's a lot of free information on the internet, but do consider what's not available there and why.
Searching as strategic exploration. Searching for information is often nonlinear and iterative (ie. requiring repetition and practice). You evaluate the sources you find, and follow leads from what you have to recognizing what else you need.
From the ACRL Framework for Information Literacy: http://www.ala.org/acrl/sites/ala.org.acrl/files/content/issues/infolit/Framework_ILHE.pdf