Who Knew?

I thought after writing my first book it would be so easy to get it published. Boy was I dreaming. I had no idea the hell I was going to have to go through. I haven't tried sending out my query letter yet. Of course I want to make sure it's perfect. After reading all of the do's and do not's, I've realized this is going to be a whole lot harder than I thought. Why do they suggest a new aspiring writer have a blog?