It seems obvious, but be sure you understand the essay question. College essays can range from writing about your hero to drafting a personal faith statement to submitting a creative writing project. Once you understand the question, do some research: Why is this question important to this college? With a clear understanding of the question and the college, you're ready to start writing.
College essays are a great opportunity to tell your story. Weave into your essay some interesting and unique experiences you've had and explain how those things have impact your life, your faith and your perspectives. College reps read these essays carefully to find out how you will fit into a college community and what gifts you can contribute.
Should you spell check? Absolutely. Use all the tools available to you to edit your essay. Grammar and spelling mistakes don't make the best academic impression. Have a teacher, guidance counselor or parent read through your essay before you submit it.
How you spend your time in college is probably going to look a little different from how you spent it in high school (goodbye study hall!) Check out these schedules from real freshmen to get a feel for how your day might look at Calvin.