To control how your web page will look on Facebook use facebook open graph markup. To check how your web page will look on facebook before actually posting it use Open Graph Object Debugger Sharing Debugger.

One my example of facebook open graph:

<!DOCTYPE html>
<html xmlns="" xmlns:fb="">

		<meta property="og:title" content="test" />
		<meta property="og:url" content="" />
		<meta property="og:image" content="" />
		<meta property="fb:app_id" content="2128533190490272" />
		<meta property="og:description" content="Yo! This is a test!" />