Lightbox

If you need to use a text link instead of a picture to launch a lightbox you'll have to manually write your links.  It's as simple as adding the following piece of code into the classic text editor of a page:

<a class="fancybox" href="http://demo.krownthemes.com/goodwork/wp-content/uploads/2012/08/image1@2x.jpg" data-fancybox-title="A Custom Title">Text Link Here</a>

If you are linking to iframes or html content, you should also add the data-fancybox-type="iframe"attribute. You can read more about fancybox here: http://fancyapps.com/fancybox/

To use a button instead of a plain text link:

<a class="rbButton dark fancybox" href="http://demo.krownthemes.com/goodwork/wp-content/uploads/2012/08/image1@2x.jpg" data-fancybox-title="A Custom Title">Text Link Here</a>

There are a couple of predefined ways to use it in the theme (WP gallery shortcode or the lightbox shortcode), but if you want more, you can do whatever you want with just a bit of custom markup!

Make sure that when embedding a video from YouTube/Vimeo/etc you only add the src.