First, use your own ideas. It should be your paper and your ideas that should be the focus.
Use the ideas of others sparingly--only to support or reinforce your own argument.
When taking notes, include complete citation information for each concept you use.
Use quotation marks when directly stating another person's words.
A good strategy is to take 30 minutes and write a short draft of your paper without using any notes. It will help you think through what you want to say and help prevent being too dependent upon your sources.