I was just reading the results of a study by Wetpaint and the Altimeter Group, which indicate that companies using social media as part of their overall marketing efforts are realizing financial gain. Brands like Starbucks who jumped on the social media bandwagon early are reaping the rewards but they've also invested the time and resources to do it right.
I've been talking with several companies over the last couple of months about social media and the implications for their business. I am an advocate for it because of a number of reasons including but not limited to realizing personal success and also because this is how people are communicating now. It can't be ignored or dismissed as "the latest thing". Growth in social networks has exploded in the last year or two and that trend is not going to change.
The best way to get started personally is just to dive into it, but I will caution you that the time investment initially is great if you are to develop a thorough understanding. If you're interested in social media for your business, start by putting together a plan or have an agency (like WhiteSpace) put a plan together for you. If you create objectives in the beginning, it will be much easier to track success.