You have to get the search engines involved, but you won't get listed by them, automatically. You have to do some work, let them know that you're there, that you want to be listed, and that you are worthy of being listed.
Get your friends to link to your blog, where your blog is relevant.
Participate in forums, where your blog is relevant, and include the URL.
Comment on other blogs, in relevant comments, and include the URL.
Share your blog, with links to key articles, in social networking sites like FaceBook, Google+, and Twitter.
Put relevant and useful content in your blog.
Some search engines may index your blog using the site feed. Be sure to activate the feed.
When you have done all of the above, your blog will have some weight. Submit your blog to the search engines, for indexing.
Post frequently, and keep the content of your blog updated, regularly.