How do you promote a blog?

Well, I started my blog about a month ago and all I have are good posts ( In my opinion ). How do you promote a blog and if possible, freely?

I have linked Twitter and Facebook, linked other blogs and also linked previous posts. I also make my headlines search engine friendly.

Now how do I promote my blog and actually get it out to the world?

How did famous Blogs and Twitter accounts promote themselves and make themselves famous when they started?