You might want to keep a copy of "The Elements of Grammar," by Margaret Shertzer and "The Elements of Style," by Strunk and White. I found a copy of "Hodges' Harbrace College Handbook," for $.99 somewhere and it is chocked full of information. In addition to your dictionary I would get a good Thesaurus also. There are a couple of URL's online that I use at work such as dictionary.com. If you do a search you will be able to pull up various sites that offer basic to advanced writing styles.