Track your ideas and new information from the start.
Avoiding pagiarism starts before you even begin writing.
As you are doing your research keep track of which ideas come from your sources and which ideas, questions, and connections you made while you were reading.
This will make citing your sources easier when it comes time to write your paper, and it helps you avoid accidental plagiarism.
The example at the right shows one way to keep track of the author's ideas and your ideas, but you can use whatever system works for you.