Your sources are the books journals or other types of material you use when you are researching for your essay.You need to make sure that you what you have read. This means that when you are researching and making notes you have to think about your plan and the question. You should be thinking about you are using the sources you have chosen and they have in your essay. Whatever points you decide to write about should include sources to support your point.
The common structure for an essay is introduction, main body and conclusion. You will have to think about your word count and decide how many words you will need to dedicate to each section. If you are used to writing short essays then you will have to bear in mind that longer, extended essays mean longer conclusions and introductions. When it comes to the main body you will have to think carefully. If your question asks you to do more than one thing you will have to make sure you have given enough thought to each aspect. Whatever your essay title, you will have to break the main body down into paragraphs. It's a good idea to talk about one key topic or idea in each paragraph. You can talk about one topic over a number of paragraphs as long as you talk about different aspects in separate paragraphs.
When you have made your notes it is important to find the most suitable place in your essay for your research to go in to. One way to do this is to make a note of the key point you are going to be talking about in each paragraph. When you have worked out your key points and placed them in a sensible order you can add the source material that is going to support the points you are going to make. Remember you can always change your plan before you start to write.