Anatomy of a search listing by Google’s Matt Cutts
Matt Cutts, a senior engineer at Google, created a video where he explains how Google creates a search engine listing for a web page (In this case he uses Starbuck’s home page as the example).
In the video he touches on many of the elements we optimize on a web page to influence those results such as page titles, meta description tags, optimizing text on the page, so it’s worth a few minutes to watch this video to understand why we do some of the things we do on a web page.
If you’d rather read about it than watch a video, they’re s a text summary over at the Search Engine Watch.