[gregmac]

> avoiding writing long documents.

Just to pick on this bit: You should still avoid writing "long documents". Spend the time to make your documentation as concise as possible. And make no mistake, making it shorter is much more effort and takes longer:

    "I would have written a shorter letter, but I 
    did not have the time." -Blaise Pascal, 1656

Nobody reads big, long wall-of-text documents. Break things into smaller sections, and be sure each section has a clear audience in mind (developer implementing initially? support debugging a production problem? QA building test cases? tech writer making user-facing docs? PM?).

Good rule to retroactively build up your docs: When someone asks a question, answer it with a link to the docs. Sometimes this means writing new documentation.