It's a start...

CyberJournalist.net has created a model Bloggers' Code of Ethics, by modifying the Society of Professional Journalists Code of Ethics

A BLOGGERS' CODE OF ETHICS

Be Honest and Fair
Bloggers should be honest and fair in gathering, reporting and interpreting information.
Bloggers should:
• Never plagiarize.
• Identify and link to sources whenever feasible. The public is entitled to as much information as possible on sources' reliability.
• Make certain that Weblog entries, quotations, headlines, photos and all other content do not misrepresent. They should not oversimplify or highlight incidents out of context.
• Never distort the content of photos without disclosing what has been changed. Image enhancement is only acceptable for for technical clarity. Label montages and photo illustrations.
• Never publish information they know is inaccurate -- and if publishing questionable information, make it clear it's in doubt.
• Distinguish between advocacy, commentary and factual information. Even advocacy writing and commentary should not misrepresent fact or context.
• Distinguish factual information and commentary from advertising and shun hybrids that blur the lines between the two.

Minimize Harm
Ethical bloggers treat sources and subjects as human beings deserving of respect.
Bloggers should:
• Show compassion for those who may be affected adversely by Weblog content. Use special sensitivity when dealing with children and inexperienced sources or subjects.
• Be sensitive when seeking or using interviews or photographs of those affected by tragedy or grief.
• Recognize that gathering and reporting information may cause harm or discomfort. Pursuit of information is not a license for arrogance.
• Recognize that private people have a greater right to control information about themselves than do public officials and others who seek power, influence or attention. Only an overriding public need can justify intrusion into anyone's privacy.
• Show good taste. Avoid pandering to lurid curiosity.
Be cautious about identifying juvenile suspects, victims of sex crimes and criminal suspects before the formal filing of charges.

Be Accountable
Bloggers should:
• Admit mistakes and correct them promptly.
• Explain each Weblog's mission and invite dialogue with the public over its content and the bloggers' conduct.
• Disclose conflicts of interest, affiliations, activities and personal agendas.
• Deny favored treatment to advertisers and special interests and resist their pressure to influence content. When exceptions are made, disclose them fully to readers.
• Be wary of sources offering information for favors. When accepting such information, disclose the favors.
• Expose unethical practices of other bloggers.
• Abide by the same high standards to which they hold other

As a journalist I only had one golden rule: Take nothing of value.