Some time ago I have read this article talking about your question right now. They have said:

Viewing any errors the search robot may have crawling your site • Setting your domain’s geographic target • Setting your preferred crawl rate (frequency that Googlebot visits your site) • Setting your preferred www or non-www domain format (not necessary if you already use 301 redirects in an .htaccess file) • Finding duplicate title and meta description tags (so you can make sure each one is unique) • Viewing your top keyword referrals • Enhancing your 404 page to include what Google thinks the visitor was looking for and a Google search box