While you are waiting for your published book to sell, consider blogging. It can be a quite lucrative way to make $$ once you have established yourself. We have seen jobs in the San Francisco Bay Area that pay everywhere from nothing to $1,000 month for part-time work, to $100/per piece.
According to MSN careers and the Bureau of Labor Statistics, writers and editors earn $42,405/year and $47,386/year, respectively
While those jobs are difficult to come by, particularly in traditional media, quite a few companies are seeking bloggers.
If you are a writer and haven't gotten up to speed yet on blogging, Web2.0, etc., you may be missing your job opportunity as a writer. Also, if you spent years on one industry, you may be in a position to write a book/eBook about that experience with tips on people new to your industry.