As always, Chris Brogan has produced a great piece outlining proper social media etiquette. It is definitely worth the perusal - and he worth the follow.
Here is another oldie-but-goodie from CommonCraft. This one explains Social Media:
Jason Menard posted a great piece on dealing with "flamers" on websites. These are angry people who are complaining loudly and at length about something. Jason's article is very insightful and helpful in finding ways to cope with such unfriendly types.
The New York Times broke a story that major American retailer JC Penney had been using fake links to propel it to the top of virtually every product search return in Google.

The search engine giant promised swift action, with JC Penney falling in many search rankings shortly thereafter.

While I am happy to see Google take action, the question does beg - if the story wasn't exposed, would Google have done anything?

There are many companies out there offering to juice websites through fake links - and businesses must be supporting them. At what point does this practice become the norm?

Simply Zesty has compiled a great list of 20 innovative Facebook marketing campaigns that is definitely worth a look through. While many of these campaigns would be out of the mere mortal's marketing budget, it's the process that is important.

The only way Facebook is successfully implemented in a marketing campaign is to encourage interaction. In other words, using Facebook to promote your business isn't about you promoting yourself at all, it's about engaging and making that interaction something fun people want to do.
Lisa Barone posted a great article on using social media for business. Her piece highlights what good practices are - that is if you want to be effective at building a network.
Author and Social Media Thinker, Mitch Joel, has posted a thought provoking piece on the changing nature of the internet. The article focuses on the sale of the Huffington Post to AOL and what this means for how we should be using the internet to network.