If you’ve ever wondered how the SharePoint Search Crawler crawls, what it’s crawling (whether it be major versions or minor versions or the associated meta data with either), I would highly recommend checking out Bill English’s article "What Does the Crawler Crawl and When?"

For those that are search aficionados, it’s a nice review.  For those that know very little on the topic and are wondering why their search results aren’t operating the way that they may expect them to (or they just don’t know what to expect) a must read.