Evaluating Sources: What is a source? An "original" source? How do I use sources for my research projects in college?
Avoiding Plagiarism: What is plagiarism? What are the consequences of committing plagiarism? How do I avoid committing plargiarism?
Since content (i.e. images, videos or text) from private or friends-only Facebook pages or profiles is not retrievable by everyone it should be cited as a personal communication.
This is great overall introduction to getting started with APA style writing and formatting.