I had a new furnace & a/c installed this summer. Warm air comes out of the vents that are near interior walls - the bathroom and the living room. The rest of the vents are next to an exterior wall and the air that comes out is cool.
What should I look at?

You shoulld get the installer back to check out his work. Could be duct work has come loose, or possibly bad design,, if he is a reputible contractor he will want his customers to be happy