SiteNow allows our clients to manage the elements used when webpages are shared on Facebook, Pinterest, Linked In and Twitter. Of course you can verify that by actually sharing your pages. For Facebook there is a handy tool for seeing how any page in your website will be shared. It even allows you to instruct Facebook to Refresh its cache for your shared page using the Scrape Again Function.
It’s somewhat technical, but you may want to have a look. Here is the link.