Social media is all the rage at the moment, and we do get a lot of enquiries about using Twitter and Facebook by business. The short answer is, yes, it can help your business, but not if you take it to extremes. You will notice some who seem to spend inordinate amounts of time tweating and posting, but beware, most of them are paid by media companies to do it. So you are much better off seeing to your business than wasting hours on twitter and facebook.
Remember your blog is still the best bet. In a blog article you can go into great detail, add images and graphs and of course links. The savvy ones will have plugins for media groups like twitter on the blog, so that way you get the best of both worlds.