My local public radio station is broadcasting an interesting program with Michael Terman(sp?) author of 'Chronotherapy' and director of a light study program amongst other academic things that flew by too quickly for me to jot them down.

The station is KERA 90.1, and the program is Think! hosted by Chris Boyd. If you go to nprDOTorg, you should be able to find it in the archives or streaming.

It has some basic information on how natural light or the lack thereof affects humans as well as some more detailed information on individual cases, how to figure out what is right for you, etc. Well worth a listen.