JD spoke at the now defunct Portland pro-bloggers group last year. Read his advice and heed it well:

From my experience, novice bloggers have no idea how much time and effort it takes to build and maintain a successful site. Yes, you can start a blog in just an hour or two. Yes, you can run a blog as a hobby, and you can even make a little money at it. But for a blog to be a full-time business it has to be, well, a full-time business. Blogging is no easy path to riches.

Based on conversations with hundreds of bloggers, my best guess is that the average blog makes maybe $50-$100 per month. (Well, the average blog makes nothing. The average blog that’s trying to make money earns about $50 to $100 per month.) A very successful blog might make $1000 per month. And some, like Get Rich Slowly, make enough for folks to earn a full-time living.

Blogging can be lucrative if you’re willing to invest the time and effort needed to make a go of it. But successful bloggers don’t just sit on the beach sipping piña coladas and eating mangoes. The full-time bloggers I know treat this just like work. Because it is work. (To be honest, the best bloggers I know are obsessive workaholics. They spend too much time on their blogs.)

Get Rich Slowly: A Demanding Task with Few Rewards?