The Purdue University OWL (Online Writing Lab) has a wide range of information about almost everything that has to do with writing. For example, the home page offers links to General Writing, Assignments, Research and Citation, the Job Search, and English as a Second Language, among other topics.
These three sites offer good advice. George Washington’s site has a helpful “Go To” button at the top right that takes you to other useful pages on time management, setting goals, dealing with stress, and strategic tips for that big test tomorrow. Princeton’s site suggests ways to study for final exams, read course material effectively, and much more.
These two sites offer help with sentence clarity and transitions: