Supporting points in academic essays show up in body paragraphs and consist of facts, data, observations, reasoning, analysis, quotes, examples—basically, anything used to show that the thesis is true. If something overheard by a couple of skateboarders in a coffee shop makes your point perfectly, heck, go ahead and throw it into the mix.
If you’re using external sources in your paper, you’ll incorporate these ideas into the body paragraphs and explain how they support your own points. If you’re not required to use external sources, or if the essay you are writing will be a timed in-class essay (better hurry before the last of that sand drops through the hourglass), then you can draw support for your ideas “with reasoning and examples taken from your readings, studies, experience, or observations,” as the SAT puts it. Look at us, quoting the SAT. Somebody is gunning for brownie points.
Usually, you’ll have a minimum of three body paragraphs in your essay, with each paragraph expanding on one point of support. You can arrange your body paragraphs in one of the following orders, depending on the quality of your supporting points: best-great-good or good-great-best or great-good-best. Personally, we’re partial to the last arrangement.