How do I use Jetpack Gallery plugin or Next-gen Gallery plugin with this theme?

If you're using a photo gallery plugin that has a built in lightbox effect, such as the ones mentioned, you should disable the Colorbox jQuery plugin in the theme by going to Theme Options >> Miscellaneous >> More Options and disabling it there. If you want the Colorbox to still apply to your featured images but not your galleries, you can alternatively open footer.php and delete lines 187 and 188. Those lines look like this for reference:

jQuery(".page-content a[href$='.jpg'],a[href$='.png'],a[href$='.gif']").colorbox(); 
jQuery('.page-content .gallery a').colorbox({ rel:'gallery' });