If you are employed, and most of us are (well, fewer and fewer of late), but most of us have a job or have had a job somewhere along the line, and there are others out there with the same job or who want to have that job someday.
So why not blog about your job?
Blog about what you did at work today or last week or last year.
Blog about your big promotion (or demotion). Blog about your bonus, your industry, your horrid manager. Let the world know what it is you do and why you do it. What did it take for you to get there are what makes you stick with it. If it is something you truly enjoy, then let the world know. If it is something you hate, then vent a bit.