The Purdue University Online Writing Laboratory - OWL - is an incredibly useful resource for writers. I have relied on this website as a reference for spelling, punctuation and other rules of writing, and they also have many valuable reference materials that could be useful to you in other classes, such as research guides and advice about bibliographical citation. The OWL is not fancy, but it is easy to use and full of helpful pages! My strong suggestion is to bookmark this site now and make sure of it often: Purdue OWL.