The thesis is the most important part of a college paper. Without one, you're not saying anything. Write a thesis and not the paper, you've still got an idea, which is worth more than a lot of talk with no direction. Simply put, the thesis is what you're trying to say with the paper. A good thesis should be posed to the writer to him or herself as a question, stated simple in the introduction of the paper, and answered through the course of the paper through evidence.
The body of a college paper is the bulk of the work. A series of concise paragraphs with a logical flow, the body of an academic paper provides evidence to support the thesis. Each paragraph within the body of a paper presents a single idea that flows directly from the ideas presented by the previous paragraph or paragraphs. The length of the body varies, depending upon the requirements of a specific assignment and the space required to reiterate, or prove, a thesis.
The conclusion of the paper ties all the threads of thought floating throughout the body and introduction together. Traditionally, the conclusion introduces no new information. The last paragraph or two of an academic paper is devoted to the final statement in support of the thesis. All of the information presented in the body of the paper is presented tightly in a handful of sentences that reiterate and summarize the idea or ideas contained within the work.
The most onerous burden of academic papers is that they require evidence. Simply put, you can't just make stuff up. You can't go on intuition. And unless you're extremely cunning or convincing, it's hard to get away with too much opinion. That said, you'll need to source everything you write. By attributing quotations and ideas to expert sources, you lend validity to your ideas and relieve yourself of countless attacks on your evidence at the hands of overzealous professors. In the bibliography, all sources should be cited as per MLA or Chicago style guidelines.
Formatting a college paper can be a difficult task. While style guidelines exist, and most schools choose to prescribe to one or another, it usually happens that professors will request specific formatting guidelines from students that contradict and supercede those of the school. However, good general guidelines are Times New Roman or Arial Font--save yourself some aggravation by avoiding Comic Sans--size 10 to 12, double-spaced and left-aligned. As per MLA style, which is adopted by the vast majority of academic institutions, use one-inch margins and indent each new paragraph half an inch.