Step1
Writing an essay is like playing a game. Just like in varsity sports where you have to know the signals and codes of the game, you have to know the signals and codes of the 5-paragraph essay. First most important word: THESIS. Learn this word. It's used to describe the first, introductory paragraph, and it's used in "thesis sentence," which is the sentence which expresses the main idea of each paragraph.
Step2
Create your essay's thesis. This is not easy. Emotionally, most students have a difficult time knowing how to "take a side" on an issue or topic, and explain their position for 300 words. The best essays are written by students who know the 5-paragraph essay is just a game (not a literary accomplishment) and feel comfortable taking one side.
For example, an essay topic might be "The Civil War." Possible thesis: "Slavery Caused the Civil War." This thesis might become the idea of the whole essay. In fact, if someone asked you, "Hey, what did you write on?" An appropriate answer would not be, "The Civil War," which everyone knows is the topic. A better answer would be, "Slavery caused the Civil War." A topic is a "place" for starting discussion; a "thesis" is the writer's own individual voice chosing sides on the topic.
Step3
The "thesis paragraph" or introductory paragraph is often the hardest to write. It consists of three sentences. The opening sentence starts the discussion going with something uncontroversial, but on topic: "The United States' Civil War was one of the most deadly and profound tragedies in history." This opening sentence, somehow, has to connect to the last sentence, or thesis, of the first paragraph: "Slavery caused the Civil War."
Now, we have a first sentence, and we have a last sentence. All we need is something in the middle, something that moves us from generalities towards specifics. How about: "While many historians have tried to argue that there were several causes to the Civil War, one cause consistently implicates all others." There! We have an opener, a connecting sentence, and a thesis.
Step4
The 5-paragraph essay is mechanical, which is why so many students feel it is boring. Writing paragraphs 2-4 -- also called "body" paragraphs -- are the most mechanical. Each follows the same structure of at least three sentences.
The first sentence is usually the thesis sentence for each body paragraph. "But, I already came up with my thesis, and now I need three more?"
A good way to write is to think, "What three things can I say in support of my main idea that Slavery caused the Civil War?" Each answer you give to your question is a possible thesis sentence for each new body paragraph.
For example, body paragraph number one, thesis sentence: "The States which rebelled against the Federal Government were all states where slavery was protected by state law." Then, the middle sentences which follow support this thesis: "Despite disagreements about the nature of federalism, Southern politicians never linked their rebellion with emancipation of their slaves." Finally, a concluding sentence: "It is evident that during the first stages of the Civil War that legally-protected slavery defined the common interests of the rebels."
Step5
There are three body paragraphs that follow the same logic explained in the previous step.
Step6
Concluding paragraphs can feel strange because they don't say anything new, really. Oh, you might throw in a quote, or add a little moral, but they don't argue anything. Instead they say, okay, here's my thesis again (in new words) and now a couple of sentences that lead us back into the larger world. Like this:
"Perhaps it is the benefit of hindsight that allows us to see clearly the causes of the Civil War. And perhaps our generation sees war for what it is: a struggle between competing economic interests. Where slavery is practiced in the world today, surely there can be no peace, again."
The
Novice 
