1- Submit your blog to Google
Open the following link and fill in your blog details. Google is king of internet so make sure to submit URL of all of your blogs.
2- Submit your blog to Yahoo
You can submit the URL of your blog or the RSS feed, both are accepted by Yahoo. Although Yahoo has far less search traffic than Google but people coming from Yahoo search stay longer on a blog.
3- Submit your blog to Microsoft Bing
Bing is the latest effort from Microsoft in search engine war. It might get a decent chunk in search engine traffic in the near future. Anyways, here is the link.
What About Less Popular Search Engines???
Some lesser known search engines like Alta Vista and Lycos use other search engines like Yahoo and Google to power their search, so don't worry about submitting your blog to them.
Tip: Make sure you also submit your blog sitemap to Google (?). It's quick, easy and free way to enhance your blog traffic.