Research about it and see what you know already and what you need to understand in detail. The next step involves picking a source; you must pick a credible source. Google Scholar or any other database can help you with that. Also, make sure that you choose a source that provides a broad perspective. You have to write citations first and write annotations later. The citation is always written at the top. Make sure that you follow the format such as APA, Harvard, MLA, AMA, or any other.