Post With A Lightbox Gallery
This page gives you an example of the lightbox gallery that is part of the Progress theme. It’s easy to use; just upload the images you’d like to include on the page/post you’re working on. Once you’ve done that, just click “Insert Gallery” and WordPress will create a stylish gallery for you at that point.
If you’d rather not use the included lightbox effect, you can just turn it off in the theme options page and the default WordPress gallery will be back without the lightbox.
Now that you know how easy it is to add an image gallery, you’ll need to find images. You can take your own, or purchase some stock images from a site like Think Stock.