What is plagiarism?
To plagiarize is to use someone else's work, whether published or unpublished, thru direct quotation or paraphrase, without giving credit to the author. Copying and pasting directly from the Internet or from online works is also plagiarism
The Hiram College Writing Center's Style Guide also provides resources to help you avoid plagiarism.
This page from Purdue University should help you avoid plagiarism: Quoting, paraphrasing and summarizing
And several more pages from Purdue University to hone your skills at paraphrasing: