What does a beginning blogger need to know?

I’m a social networking dumbdumb. Fluther is about as close as I get.
I like Tumblr, I want to start something there. The problem kind of being that I don’t think anyone wants to read about my random stuff. It’s a self confidence thing and I think if I can get started on a blog, then it’ll help me be more open with people outside the internet. That might sound weird because I’m stilling thinking this through.
I’ve seen some people have here have blogs and the like. It’s odd because it seems simple, but I have nowhere to start. I’ve looked on Google and it’s too much information everywhere. Any help or suggestions as how to start or where to begin?