A few ways. I happen to live in an area of the country surrounded by military bases, and consider many members of the military (and their families) my friends. My family also has a long history of military service, and it includes cousins who've spent time in Iraq and Afghanistan. From these people, I was able to obtain first-hand accounts of what life is like and have specific questions answered. I supplemented that with vast amounts of reading (books, self-published books, military blogs, articles, and public information provided by the U.S. Military). It's also possible to view snippets of various military engagements via YouTube. I tried to do my best to make everything as accurate as possible.