When you quote, paraphrase or summarize someone else's work or ideas in your paper, you MUST cite your source. If you don't and try to pass off their work or ideas as your own, then you are PLAGIARIZING.
When mentioning someone's ideas in a paper, there are several ways to do so. Here is a great website that explains the difference between quoting, paraphrasing and summarizing. The website also has great examples of how to use all 3 in your assignment.
There several ways to cite. Should I use APA or MLA? APA is used by Education, Psychology, History and the Sciences. MLA is used by the Humanities (Literature).
Try this website if you need help creating an APA citation. Try this website if you need help creating an MLA citation.
Here is a great website to go to if you need to create an APA citation from scratch. Here is a great website to go to if you need to create an MLA citation from scratch.
At the end of your paper you will need a Works Cited page if you are using MLA or a Reference List if you are using APA. Basically you will need a separate page that lists all the sources you mentioned in your paper. Here is how to create a APA Reference List. Here is how to create a MLA Works Cited page.