Okay so I've been meaning to blurb out a bit about one of the more interesting houses in a chart, the 'hidden' 12th house of the Unconscious, Self-Undoing; Karma, and more. 12th house is a Psychological house along with the 4th and 8th...deep, very deep.
Having a planet there natally myself, I've always found it to be a fascinating part of any chart...even if it does relate to politicians who so often have 12th house planets (natally Bush has a 12th house Sun--unconscious arrogance, among other things.)
One of the most useful astrology books I discovered early in my reading was Tracy Marks' Your Secret Self: Illuminating the Mysteries of the Twelth House. It's available on amazon.com I know because I reviewed it there years ago. My advice is to procure one if you can--if you don't already have a copy.
But if you're wanting to get some 12th house info right now you'll want to read Robert Wilkinson's article the 12th house on his excellent Global Astrology blog Aquarius Papers.
Now that would be my best advice!
UPDATE Saturday: Philip Brown is shining a light on the deep dark recesses of the karmic 12th house as well. Check out AstroFutureTrends: Astrology of the 12th house where you'll find Philip's analysis plus 12th house quotes from Dane Rudhyar, Howard Sasportas, and more. Great work, Philip!