I responded to your other post about this topic and suggested some avenues of possible research. Once you have thoroughly explored the topic, you should be able to choose whether you are pro-organic or not. There is a wealth of information available on this topic.
In organizing your final paper on the topic, you should create a thesis to support your argument. Your thesis should include: the topic (organic food), whether or not you believe it is best for the consumer, and three supporting main ideas (these will be your main body paragraphs). Example: Although widely praised for being a healthier choice, organic food is not the best option for consumers due to availability, overall quality and shelf life, and high prices.
Then, in your main body paragraphs, you can further your argument for each subtopic by providing research and evidence to support your overall argument.