You have found a good site for help in writing and also in detecting plagiarism in your papers. I see that this site lets you view essays on various topics. Please do not be tempted to simply use one of those papers as your own. Many teachers these days use online plagiarism checkers. And by simply typing a line or two from your submitted paper, a plagiarism check can return the exact original paper to the teacher word for word.
I have added a link for you below. The OWL writing lab at Purdue University is one of the most comprehensive I've ever seen. I refer my online college students to this lab.
Enotes has many useful study guides for you as well. Please check out the links below.
There are many useful links available to you at enotes as well.