"military fiction with a touch of romance". Your genre interests me because it is the closest to the kind of thing I'm working on. I've been on this site for almost a year, and it seems to be dominated by people writing fantasy, science fiction, or children's books.
I did seven years in the Air Force, and part of my book is based on those years. Those were the easiest scenes to write, because I most empathized with my protagonist when he was one of the troops.
I'm not optimistic about the market for such a book, and lean towards self-publishing.
Over a period of time, I'm sure you'll find plenty of useful information about agents, book publishers, etc on this site, or in the Writers Digest magazine.
Good luck.

Very few publishers will accept work directly from writers. You'll need to get an agent if you want to get published from any of the major publishing houses. You can always self publish, though if you have the upfront capital and feel confident in doing your own promotions. There are some minor publishers that will take your work. It all depends on how far you want you want to go. If you have big dreams, you'll need an agent. If you just want to express yourself, you can do it yourself.