On the proof album pages, you will see a filename along with each image. For example: "IMG_2184.jpg" or "IMG_2157b.jpg". That is how you will identify images for your print order or if you have questions about any particular image.
Click on the "Order Prints" link from the main album page to open a new email window.
Enter your print order as an email, indicating which images you want for each desired size and options. For example: