So Long, and Thanks for the Ph.D! This is my favorite guide by far.
How to read a paper, CCR, July 2007.
Writing Technical Articles, by Henning Schulzrinne
Common Bugs in Writing, by Henning Schulzrinne
Top 10 tips for writing a paper, by Jim Kurose
"How to write a paper", by Oded Goldreich
The Free Dictionary Online dictionary
Merriam-Webster Online Another online dictionary
Guide to Grammar and Style, by J. Lynch
alt.usage.english FAQ, addressing common grammar questions