To connect two mobile homes together as one, you need to strip the sidings from each mobile home. Then, build framed sections and align the boards to match up the frame. Secure the built sections onto the existing walls using heavy duty steel bolt. Build doorways for the trailers and insulate the space left between them. Find detailed instructions from http://www.ehow.com/how_7994178_join-wide-mobile-homes-doublewide.html.
I saw someone do that. They built a front entrance/foyer between the two as a joiner and used 1 home for living room/ kitchen/ bath and the other one they stripped out and made two large bedrooms with baths
I've built mobile home parks and set 100's if not more mobile homes. Are you talking about 2 single wides or is this a double wide that is just not set together yet?. If the home isn't a double wide and were talking about 2 random units I need some pics and u need some skills ;-) it can be done but rarely for less than you could just buy a used double wide