Plagiarism

It is Common Knowledge: 

• If you could easily find the information in 3-5 other sources. This includes historical dates and facts, even if you don’t personally know it.
• If it is general information that most people know. For example, George Washington is the first president of the United States.
• If it something that is know within one field. In the field of biology everyone would know that mammals have hair.

When in doubt, cite it!