For requirements to become a pilot, i would start by looking at the www.
Faa.Gov website. For sport pilot requirements, an excellent starting point is www.Sportpilot.Org. For requirements to be in an armed forces branch, each branch has its own website. Remember there are general armed forces medical requirements -http://usmilitary.About.Com/od/joiningthemilitary/a/intmedstandards.Htm.