Google has just launched another beta service: Google Blog Search. It looks pretty good already, and for example searching for relevant phrases brought up the expected postings from my blog. There is no way to explicitly submit a blog to Google, and the key to getting your blog listed is to submit it to relevant blog lists, which is most easily done by pinging a service such as Ping-o-Matic. If you're using a nice blogging tool like WordPress, it should automatically take care of this for you.
Somebody has written up a nice comparison between Google Blog Search, Blog Pulse, Technorati, and Ice Rocket. While Google still appears to be playing catch up in a few minor areas, they already do what they do best: provide lightning fast access to relevant search results.