First, use your own ideas. This is your paper, and your ideas 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 item 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 your being too dependent upon your sources.
Are you using images from the internet in your paper or presentation? If so, ensure that you are not plagiarizing the images by citing your source. You can use Google Image Search Tools to filter your results for images labeled for reuse (no copyright/license restrictions). Note that you should still cite your source even if the image is labeled for reuse.