I suggest you first check the U.S. Citizenship and Immigration Service (USCIS) homepage by clicking here:
You should also speak with your commander as he/she may have advice as well and can probably direct you to the legal or other office which can probably provide guidance and assistance.
Depending upon whether you are stationed in the U.S. or overseas I don't think the process will be any different than for a civilian in the U.S. seeking to bring their fiancee to the U.S. I am basing this on the fact that when I was bringing my fiancee over, I saw men in uniform in the local USCIS office going through the process of applying to bring their fiancee to the U.S.
Good luck and thanks for your service.