Better way to display images

Hi guys,

I am looking for a way to improving the image viewing experience for my readers. I am currently adding images sized to the content area which is 624px. Readers requested, that they would like to see the images in a bigger format.

How can I best do this? I think it would look nice, if once people click on a single image, it would open in a lightbox, with a black background, in a bigger size. How would I go about this?

Thanks for your help,

Philipp