Ohio University has put together this good collection of links about the writing process. There, you'll find good tips on things like narrowing your topic, brainstorming, stating your thesis, and much, much more.
Here are a half-dozen quotes from prominent writers about revision. (There are some other good quotes there, too.) How can a carefully chosen quotation strengthen a paper?
Here's The Elements of Style(1918 edition) in etext at Bartleby.com. It's a book every writer and reader should know.
Be sure to check out this directory from Google.com concerning FAQ's, Help, and Tutorials on topics from "writing for the web" to "curing writer's block."