Paul Boutin, who writes for Wired and the gadget blog at NYT, has some useful advice for group blogs (multiple authors contributing to one or more blogs):
Hire someone to handle all images for posts, so your writers can focus on writing. Beyond that, a good editor will turn good bloggers into better bloggers by helping them improve weak passages, by teaching writers to fill their posts with context and clarity, and sometimes by shooting down a post that just isn’t working.
For all this, your writers will hate them. But readers will love it.