If you use any information from any source (print or nonprint, including websites), you must quote or paraphrase that information and cite it. The only exception is for information that is common knowledge. Example: the months of the year or the planets in our solar system.
If you are unsure if it is common knowledge, then you should cite it.
Examples of resources you might use that must be cited:
All guides are available under the CC-BY-NC-SA license.