Dan Gillmor, whose blog I’m fond of and who is a friend of Bumblebums, distills “Journalistic Ethics, Codes of.” And it applies, I think, to blogs:

Turns out there are bunches of [codes of ethics], as Len Witt notes. I tend to go with Jeff Jarvis’ notion that the basics are pretty simple — “Don’t lie. Don’t sell out.” — though the devil, as always, is in the details.

I tend to bring it down to this even tinier admonition:
Be honorable.