Here is a great new article from one of the old gurus of solar.
http://www.solartoday.org/2006/sept_oct06/Passive_Solar_Cb_SO06.pdf
Doug Balcomb (the author) helped many of us early adopters to adjust solar techniques and develop simulators for the performance of different designs. I used Balcomb's research to build a passive solar calculator using a spreadsheet on my Commodore 64 computer! (Bet you can guess when that was. :D)
(http://img235.imageshack.us/img235/2017/dougnn6.jpg)
(not all of the above systems work in all climates)
One of the things I've learned is not to get too excited about what works in New Mexico when you live in a cloudy Northern climate.
For my distilled wisdom (such as it is!) about what does work see the SunKit (http://www.countryplans.com/solarkit.htm).