Amateur Needs Serious Help Picking Paint Colors
It seems like you have a lot of browns/neutrals going on and (even thought I don't know what your house looks like) I would say an accent wall would be nice. Then again, I'm not a huge fan of all-over, in-your-face color.
One thing you could do is take a trip down to Pier 1 or some other home type store. Pick out your favorite throw pillows for your new couch and maybe a lamp that goes with for your end table. The accent color in your choice of pillow will be a huge clue as to what color you guys what for an accent. Having color on an accent wall that is picked up in the accessories usually works out well.
For example, and just to help explain what I mean, I knew I wanted neutrals in my living room with a pop or two of color. I found a chair with a similar print to this pic and worked all my design choices around it. Now everything goes.
Or, the previous poster had a good suggestion. A lot of the paint stores have easy to use programs that enable you to upload a pic of your room and virtually "sample" all of their colors on your walls.