Bigelow Aerospace has prepared some really great photos and a lot of fantastic artwork to communicate its plans. Perhaps in the future, the company's web site will take on a more finished professional look to highlight these pictures and artwork.
The following rendering is of a single Nautilus module, with volume of about 17,000 cubic feet from the outside dimensions. I guess that would be very roughly 11,000 cubic feet internal volume, a little more than twice the volume of my Washington condo apartment. This is plenty of living space for one or two people accustomed to the American style of living, so long as some privacy is afforded by walls and maintenance areas (trash room, water system, etc.) are kept to a minimum.