How to get Gallery Thumbnails to open into a popup page with image and text?

Hi,

I am looking to repeat the effect I’ve found in this page here:

http://turtleclanart.com/pages/store.html

or here

http://turtleclanart.com/pages/gallery.html

I want to be able to link a gallery thumbnail to an editable WordPress page with the thumbnail image and be able to add editable text next to it.

What WordPress plugin will enable this ability? Or how is it done?

Thanks,

John