When you find your photo(s), to purchase, click on your selected shot(s), and after that image is featured, click on the green "Buy" button. You can select the "Prints" tab (sizes available are 4x6, 5x7 and 8x10) or "Downloads" tab (low/hi-res jpgs available) for purchase options.

If you participated in last years event, you can find that gallery here: http://madeyalookphotos.smugmug.com/Sports/Aurora-Duathlon/