This is the most difficult of the sources, You make a request in writing to the Still Picture Branch. They will send you Xerox copies of images available and the image unique image number as well as a list of authorized contractors. If you decide to purchase an image you contact a contractor from the list and prepay for the service. They will then go to the archives and pull the negative and make your copy and send it to you by 1st class mail. The whole process takes about 4 weeks. Prints cost an average of $20.00 each.
Easiest of the sources, You make your request by mail or by phone, there is also a printable form on their web site
You make your request by mail, instructions can be found on the Naval history Web site http://www.history.navy.mil
You make your request by mail, see their web site for further information,