Submit your blog url to Google at: Add your URL to Google.
A better idea is to add a Google sitemap to your blog. Go to Adding Google sitemap to your blog to learn how.
You may also submit your blog to Google Base and include a link back to your blog.
You may also submit your url to Yahoo! search for free at http://submit.search.yahoo.com/free/request
For submission to MSN, go to MSN url submission.
Generally it is not necessary to submit your url to search engines nowadays as eventually the search engine will crawl your blog. There is no harm in submitting though. A faster way to do it is to get a link from websites that are already indexed by the search engines as they will automatically follow the links to crawl sites that are linked there. If you don’t know anybody who can link you, you can submit your website to blog directories. An easy one to submit to will be My Blog Directory (it is already indexed). Just go to the bottom of the directory and click “Add your blog”. (You may want to read more about how My Blog Directory may help you get some extra traffic to your site. Go to “How to make a blog directory for your blog“. Other blog directories you can submit to are Blogwise, BlogCatalogue, Bloggernity, BlogFlux, GlobeOfBlogs. You may also “claim” your blog at Technorati.