Every site out there now ends up being shared on Facebook. If you want your site to look good on a person's wall or in the news feed when it is shared you need to include Open Graph protocol tags.
The first step to seeing how your site appears is going to Facebook's URL Linter tool. Here you can enter in your site's URL and it will tell you how it will appear on Facebook. You will notice there are tags such as "og:title", "og:image", etc that you can include on your page that will allow you to control how Facebook displays the text and icon associated with your site when someone pastes it into Facebook.
For example:
<meta property="og:title" content="The Cloud Construct Blog" />
<meta property="og:description" content="The Cloud Team's Thoughts, Ideas, and Expressions." />
<meta property="og:type" content="blog" />
<meta property="og:url" content="http://blog.cloudconstruct.com" />
<meta property="og:image" content="http://blog.cloudconstruct.com/images/fb-image.png" />
These would be great properties to include on the homepage of my blog site so when people linked to it on Facebook it appeared correctly and served up a nice image with it. If Facebook decides to display pages of type=blog different than a website it also can do that too. Basically, you are conforming to the Open Graph standards so all sites who choose to dispay your site can do it in the best way possible. The image has specific standards such as being 50x50 and certain file types. After you place the above tags in your page, you will want to read this Facebook Tutorial about adding the appropriate html namespace tags as well:
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:og="http://ogp.me/ns#"
xmlns:fb="http://www.facebook.com/2008/fbml">
There are tons of tags you can add to make your site even more inline with the OG protocol. See the Social Graph options on the Facebook site.
Lastly, when you run the URL Linter on your site it will update your site in the Facebook cache. So if you are not properly indexed now, run the tool after you update your site and it will update Facebook's cache.
NOTE: Although I am writing this article and the Cloud team places these tags in all of our newly developed sites. We still have not had time to put it on our own site. Please don't hold that against us :)
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