Chris, over at Ruminate, forwarded a request for help from Tammy, a new EduBlogger.
Looks like she was inspired by her time at the WCET conference. And it looks like she doesn't suffer from the fears I had when I started blogging.
I've been at this 2 years now (Yikes!) and the only advice I have (beyond "Just do it") is to write about what interests you. I personally use this as a diary / therapy tool for my professional life. Within certain boundaries (yes, my current bosses read this blog), I talk about projects and interactions within those projects because I felt there wasn't enough of-the-moment, in-the-trenches case studies available. The ones where the person is writing from within the project and has no clue whether what they are doing will succeed or fail.
That and writing it all out makes me feel better.
Other bloggers in the edublog space talk about cool new toys, or new research, or provide advice based on their own experience. Some are more personal than others.
Your blog will morph and shift and take on a life of its own. Your blog may spend moments neglected and unloved, then suddenly be smothered with attention from you and your commenters. The edublogging space is incredibly friendly and an awesome source of feedback.