These links go to information that covers only those grammar, punctuation, usage, and spelling problems that give people the biggest headaches.
Technical-writing professionals try to simplify grammar rules as much as possible, without hurting the language or putting themselves in straitjackets. Typically, they work in teams and frequently move in and out of projects—so that the same document may be worked on by different writers and editors during the space of just a few years. That's why any guidelines based on interpretation or personal style or judgment must be avoided.
Here are some other sources to consult:
Brian Garner. Garner's Modern American Usage. Oxford.
grammarbook.com. Provided by Jane Straus.
Guide to Grammar and Writing. Provided by Charles Darling at Capital Community College.