Webmaster Tools,one of the free tools offered by Google is an extremely useful tool for a webmaster.Once your site is added in webmaster, this tool tracks various factors which helps in improving the status of your site.

Once your site is added, and you click the site name, you will be taken to the dashboard.The dashboard lists all the options available for a site.This includes

• Site Configuration
• Your Site on the web
• Diagnostics

Following are the most important factors:
Site Configuration:
Site Maps : Enables the user to submit sitemaps
Crawler Access : This option enables the user to disallow Google from crawling pages.
Site links : Google generates these site links(internal links to a site) automatically.
Change of site : Guidelines to move your site to a new domain.
Settings : Includes options for geographic target, preferred domain, crawl rate

Your site on the web:
Top search queries: List the keywords which were queried and the positioning of the
keywords for your site.
Links to your site : Displays the list of internal links to your site.
Internal links : Displays the links which links to your home page.

Diagnostics :
Crawl errors : Provides information regarding crawling errors by Google
Crawl stats : Graphically displays the Google bot activity
HTML Suggestions : Issues detected by Google in the content of you site

An indepth discussion regarding Webmaster tools can be viewed in the following forum v7n.com/forums/google-forum/111170-do-you-use-google-webmaster-tools.html.