I've mentioned my enthusiasm for Sam Shah's outreach to new math edubloggers, including his how-to guide for getting started. I contributed a video profile to his project where I try to describe why getting a blog has been such an awesome, weird thing for my career and then convince you to get one yourself:
Hi my name is Dan Meyer and I've been blogging for six years. I still remember the day I set it up — just a casual decision to create a free blog. I blogged not because I wanted a huge readership but because I wanted to debrief myself after particularly good or bad lessons. I wanted to be able to read about it later. That's it. But it turns out people like reading about that sort of thing so I slowly got a readership and even with a small one I started getting so much better as a teacher. I would ask for feedback explicitly. I would throw some praise on the people who offered critical feedback. That's not easy to do. And the result of all that critical feedback, I'm pretty sure, is that I grew two years of professional growth for every one year I was in the classroom, which is totally unscientific there, but that's how it felt. I'm pretty sure that without my collection of blogs and readers and critical comments, I'd still be back there totally psyched about that amazing worksheet I came up with. So give it a try. Get a blog. Write for yourself. Let other people know about it. And above all have fun.