You can use some code like this:
<div class="share-buttons-container">Share this via
<a class="social share icon facebook" target="_blank" href="http://www.facebook.com/sharer.php
?u=<%# System.Uri.EscapeDataString(CurrentDocument.AbsoluteURL) %>
&p=<%# System.Uri.EscapeDataString(CurrentDocument.DocumentName) %>"></a>
<a class="social share icon twitter" target="_blank" href="https://twitter.com/intent/tweet
?text=<%# System.Uri.EscapeDataString("Great Info: "+CurrentDocument.DocumentName) %>
&url=<%# System.Uri.EscapeDataString(CurrentDocument.AbsoluteURL) %>
"></a>
<a class="social share icon pinterest" target="_blank" href="http://pinterest.com/pin/create/button/
?url=<%# System.Uri.EscapeDataString(CurrentDocument.AbsoluteURL) %>
&description=<%# System.Uri.EscapeDataString(CurrentDocument.DocumentName) %>
"></a>
<a class="social share icon email" href="mailto:
?subject=<%# System.Uri.EscapeDataString("Look at this great info!")%>
&body=<%# System.Uri.EscapeDataString("I thought you'd like this: "+CurrentDocument.AbsoluteURL) %>"></a>
</div>
You can get what the URLs are from the respective social platforms developer documentation.