Give credit where it is due, it is the smart (and ethical) thing to do.
Avoid plagiarism by citing sources.
Citing a resource properly should allow another person to RE-search out the item and find the exact same content that you did.
Q: How do I write a citation?
Ask your teacher what style they prefer.
Use cite suggestions provided by databases when available.
Ask your teacher if the database cite suggestion is good enough, or whether you need to further check your style with a style manual (especially in technical and upper level writing courses).
Copy/paste cite suggestions to a Word document and alphabetize yourself, or use a ciation manager.
Only use one edition and style in a project.
Citation Manager Comparisons
YouTube: Why Cite?