Social Bookmark your blog on sites such as StumbleUpon, Propeller, Delicious, Reddit, Digg. Social bookmark really good articles that you spent a considerable amount of time on that that are of really high quality.
Submit your RSS feed to RSS directories. Just Google "RSS Directory", this will help to spread the word about your blog.
Join BlogCatalog.com and participate in the community there to promote your blog.
Guest blog on a really popular blog within your niche.
Join a blog carnival and submit an original post, this will instantly drive HUGE amounts of traffic to your blog.
Participate in forums related to your blog.
Join social networks such as Facebook and Twitter; get involved and follow people who are related to your niche.
You can get more blogging promotion tips at Blogging For Dollars.