There have been discussions on this forum about guidelines for various social media options, below are links and content from three different reputable sources regarding Twitter use. Check them out and post some thoughts.

UK Govt guide to Twiiter

Mashable Twitter Guide Book

And from the Wall Street Journal, an excerpt on Twitter use from an overall social media user guide.

“Let our coverage speak for itself, and don’t detail how an article was reported, written or edited.

Don’t discuss articles that haven’t been published, meetings you’ve attended or plan to attend with staff or sources, or interviews that you’ve conducted.

All postings on Dow Jones sites that may be controversial or that deal with sensitive subjects need to be cleared with your editor before posting.

Business and pleasure should not be mixed on services like Twitter. Common sense should prevail, but if you are in doubt about the appropriateness of a Tweet or posting, discuss it with your editor before sending.”

Thanks for sharing these links. I totally agree and I like the advice from the WSJ about not leaking unpublished news. Also, I would add never to malign a client's hometown like what happened a few months ago on Twitter -

Your comment goes hand in hand with the post I put up about going too hard after someone who tweets something negative about your company.

I always get a kick out of how the British Govt seems to overreach in their efforts to cover all potential issues. Talk about meticulous.