I know when I started down the path to becoming a professional photographer I had A LOT of questions. I wished there was just someone I could ask for advice who had climbed the mountain I was attempting to climb. Oh I guess Zack Arias heard my prayers, because on his tumblr that's exactly what he does.
Zack has dedicated some of his time in his very busy life to sit down and answer questions from those of us who aren't quite there yet. He answers everything from technical gear questions, to business questions, to lending his opinion when asked. I think it is really awesome that someone like Zack is giving back to the photographic community on such a personal level.
Now don't get upset if he doesn't answer you right away, I think last time I checked he said he had over 800 unanswered questions, but he has answered so many that a quick search of his blog might turn up an answer you are looking for. Don't have a tumblr account but want to ask a question? That's easy, he has made it possible for people to ask questions anonymously without a tumblr account. I would still recommend searching his blog first though before submitting a question, as there is a great chance he has answered it already.
Here are a couple of examples.