When it is time to gather all of your notes and start writing the paper, avoid the most common mistake - plagiarism. Plagiarism is not only taking large parts of someone else's work and not attributing credit to that author; paraphrasing sections of a work, even using synonyms and citing the work, is also plagiarism.
Even if the ideas are rewritten, the source of the idea must be cited and the author given credit.
Online documents can be particularly problematic because they make it very easy to cut and paste information without thinking and without giving proper credit. Make sure you understand how to cite your sources.
For more information about how to avoid plagiarism, see this video at our Research Den.
Here is a tool that can help you cite your resources properly.
Please note: There are citation generators online that can help--BUT USE THEM WITH CARE. They are not always accurate, so you need to doublecheck the results.