In your papers, you should provide sufficient, correctly cited support that substantiates your ideas.
Even research papers only use sources as support, not in lieu of original thought from you, the essay's author. Use sources that enhance your ideas, but don't let other people's work stand in for your own. If you're writing or presenting a research assignment, don't just assemble other people's ideas. Think of your sources as your big brothers backing you up in a fight, but not going in the melee instead of you. You should connect what you're writing to the source material, and then explain the source material's relevance. Don't let a quote just hang there unexplained, and never end a paragraph on someone else's words. Always, always tie up a quote with your own words.
You need to be fair and accurate: don't take quotes out of context or spin summaries to suit your own purposes. If the material you want to use doesn't really support your point, find other material that does.
The Graduate School standard is APA documentation. Reference your sources appropriately and accurately (not by the source's first name, for instance, and not by only one name if it was a group project). If you don't know APA documentation, check your APA guide, or go to the UMGC library, or search online for the example you need. Many people find the idea of citing or of using a particular format stressful, but it needn't be. It's finicky, and it's nitpicky, but it's really just following a template. If you can follow a recipe, you can follow these guidelines.