There are a number of things you can do to boost your blog traffic, but first, you should understand that building an audience will not happen overnight. Here are some suggestions:
1. Keep your blog current. This is perhaps the most important. Posting at a minimum of 2-3 times each week will keep people interested and engaged, and thus likely to share your content with others. Neglecting your blog even for a week once in a while will hurt traffic.
2. Use social media to drive traffic. This goes beyond spamming your friends list with "read my blog" posts. Seek out groups with similar interests and get involved with them. Post useful comments in those communities and like-minded people will eventually look to your site for more information or material.
3. Be sure that your e-mail signatures contain a link to your site. We send out a ton of e-mails to people all the time for all sorts of reasons, but a small link at the bottom reminds our friends that we blog.
4. Look for other similar blogs - many times upon polite request, other bloggers will write a guest post for your blog site, which sometimes drives traffic as their followers/searchers will find them, and thus they will find you. Many very popular people have been known to do this.
5. Use photos/videos effectively in your blog. Studies have shown that people are much more likely to share a photo or video. I have found that the "reach" for photos I post is often 5-10x that of text-only posts.
6. Talk about hot topics and use keywords effectively - this helps strangers find your blog. Blogging about the latest TV shows or songs or whatever is popular in the news, depending on your audience, is a good way to pull a bit of traffic in from people who are using search engines to looks for those topics. Google has a few tools that help you find keywords. I recommend that you use a keyword in the post's title, then use each keyword approximately once per 100 words of text. Repeating the same words again and again looks awkward, and sometimes the search engines will actually avoid your site.
7. Link your blog posts to each other - especially if you have written a series of posts on the same topic - people who actually find one post through a search engine may want to read more about it, so including links to previous posts, as well as your Twitter or Facebook link at the bottom of your post, will also help build your fan base.