English essays can largely follow a basic framework, depending on the type of question you are answering. If you are comparing two books you can break down the essay into; introduction, first book, second book, comparison of the two books together, and conclusion. A solid introduction and conclusion are helpful in framing your argument and making it convincing.
However structure alone won't make an essay convincing. Your structure should enhance your argument and lead your reader/examiner easily from point to point. The key to doing this is planning your essay in advance. Think of the main points you wish to cover and examples of these points within the texts. Then write them down and put them in an order which naturally will reinforce and refer back to your overall argument.