Back in 2009 (wow, that's almost two full years ago now), Google gave the semantic web a search-engine bump with Rich Snippets, their own implementation of a collection of semantic standards (RDFa, microformats, microdata). Select microdata were later reorganized into schema.org's more-broadly-supported collection (Google, Bing, and Yahoo are all behind the site) -- and schema.org recently expanded its semantic horizon with new RDFa 1.1 Lite support.
All of which is certainly a good thing. But while the microdata and RDFa standards are simple to grasp at a high level, the actual implementation can get a little more difficult. You'll need to decide a lot more about what different kinds of sections each page has -- not just where the sections are delineated -- which in turns means fitting together the different sections of your whole site, in a way that coheres with the various divisions within each individual page.
No worries, however, for Google has just released a series of instructional videos detailing what Rich Snippets are, how they work, and how you can use them to benefit your site maximally.
The introductory video is embedded below. It presupposes absolutely zero knowledge of HTML5 semantics, though, so if you're already familiar with microdata, microformats, and/or RDF(a), then you might want to skip to the whole YouTube channel and flip through the more advanced videos. All videos are no longer than a minute or two, so time investment is minimal.