This guide from the Purdue OWL walks you through the basics of paraphrasing, using research, fair use, and avoiding plagiarism.
Be Wary of Automatic Citation Generators!
Many databases offer the ability to auto generate a citation. It's OK to use these, but always be sure to double check them, because quite often the computer may get some of the formatting wrong. (for example, an extra space, a missing comma, etc).