Click on a small thumbnail photo to view the larger popup photo.
While viewing the larger popup photo, click the keyboard right or left arrows to go to the next image (respectively). You can also click the left side of the photo to go back or the right side to see the next photo. Click the close button or anywhere in the dark background to close the image.
To download a high-resolution photo, click the thumbnail to view the larger photo, then click the "high resolution link". This will open a new window with a photo that should print nicely at 4x6 inches. Right click the image to save it to your hard-drive, which you can then print.