advice out there for personal bloggers: creating your voice, telling stories, etc. But for corporate bloggers, creating compelling content has to be compelling only to potential customers. It needs to answer their questions and solve their problems. Plus, SEO is critical, and not just to turn up high on all searches: to turn up high on relevant searches. Another reason I am in love with the cases of Aprilaire and this mixed martial arts blog.
I'm rethinking the wise-ness of doing a trial with my company's blog. Maybe it's better to try first entirely on the outside. There might be an opportunity to do a test blog with a business I know - and possibly they'll trade some services (they're a photography studio/event space). I'll see what their goals are, try out some keyword research programs, and see if I get any traction. If it works out I'll post some results.
By far the most helpful Web site I'm using right now is Copyblogger. It's providing me with the resources to really start building something.