To avoid plagiarism you must clearly--within the body of your paper or report--credit the source of every fact and idea that:

• is not your own
• doesn't fall into the category of "common knowledge" (e.g., Abraham Lincoln was the 16th president)

Learning to do this is a skill that takes thought and practice. When in doubt, cite the original source. You can always consult your professor, a tutor, or the Writing Center for advice.