Google has re-arranged the menus in Webmaster Tools:

Features are now organized according to the stages of search: crawling, indexing, and serving. The settings have moved to the gear icon in the top right corner.

A new menu item has appeared in Google Webmaster Tools to help webmasters understand what influences snippet generation and the appearance of sites in search results. For many SEOs, there is nothing new here, but for smaller businesses unable to afford search consultancy it will provide useful information and drive home the need for clear site architecture and the need to use semantic markup or structured data.

If you hover over the individual elements, then additional information and links to Google guidelines are shown.

For example, sitelinks are generated algorithmically and those sitelinks chosen to be shown are related to the query entered:

The following screenshot from Google Webmaster Tools shows the help presented for influencing the URL appearing in search results. In this case, the advice is to either have a clear site architecture, or to add breadcrumbs.

This additional information is very useful for site owners and provides a good point of reference for many smaller businesses hoping to optimise appearance in search.