What do I need to do beore im married?

Alright so Im getting married in October in KY to my boyfriend who is in the army and is stationed at Fort Campbell. But in July he is going to afghanistan until October, and as soon as he gets back im going down there and we are going to get married. It just going to be in a courthouse or whatever its called. But how do I go about getting all the doents, what do i need to do before we do get married? What doents do i need? how do i find a courthouse and do all the stuff if im in CT?