Schema.org, Open Graph, and Twitter Card meta tags

<!-- Place in head of website -->

<!-- Schema.org markup for Google+ -->
<meta itemprop="name" content="{Site Name}">
<meta itemprop="description" content="{Description}">
<meta itemprop="image" content="{Site logo -  URL}">

<!-- Twitter Card data -->
<meta name="twitter:card" content="summary">
<meta name="twitter:site" content="{Site Name}">
<meta name="twitter:title" content="{Page Title}">
<meta name="twitter:description" content="{Description}">
<meta name="twitter:creator" content="{@handle}">
<-- Twitter Summary card images must be at least 120x120px -->
<meta name="twitter:image" content="{Logo or Image - URL}">

<!-- Open Graph data -->
<meta property="og:title" content="{Page Title}" />
<meta property="og:type" content="website" />
<meta property="og:url" content="http://www.example.com/" />
<meta property="og:image" content="{Logo or Image - URL}" />
<meta property="og:description" content="{Description}" />
<meta property="og:site_name" content="{Site Name}" />

For reference, see: http://moz.com/blog/meta-data-templates-123