We all work in different ways, and how we approach research and writing is no exception. However, there are some basic principles in this process that might help you to avoid losing track of your sources, or inadvertently plagiarise.
In the research phase:
Notes: When you take notes from sources, make it clear when you are copying verbatim and when you are putting things in your own words. Always keep a record of where you read the information.
When you refer to a source in your own work, you can either:
Paraphrase: Rewrite a sentence, paragraph or idea in your own words. This can help to demonstrate that you have understood the argument and the academic context.
Quote: Use the exact words of the author, in quotation marks.
Whenever you quote, or paraphrase, another person or source you should:
Cite/reference: Cite all sources correctly according to the appropriate system.