Karla's Guide to Citation Style Guides
This web site is a great directory of pages that explain how to cite sources using a specific style, such as APA or MLA.

Sources: Their Use and Acknowledgement
Created by Dartmouth College, this site provides information on citing sources, example citations, and useful resources. Their selection of examples are wonderful. If you need help doing you bibliography, you can't miss this site.

Guide to Grammar and Writing
"The Guide to Grammar and Writing contains scores of digital handouts on grammar and English usage, over 170 computer-graded quizzes, recommendations on writing -- from basic problems in subject-verb agreement and the use of articles to exercises in parallel structures and help with argumentative essays, and a way to submit questions about grammar and writing."

Proposal Writing Short Course
Published by the Foundation Center