As there are so many documents of Catholic doctorine that are considered infallible in content, how to search them? In other words, how to track down very particular pieces of infomation or answers...Obviously one can't read the entire lot every time one has a query! Is there some online resource that makes it easier?
Your best source for Papal Encyclicals (official statements of the Pope ex cathedra) comes from the Vatican itself comes from EWTN.  Check out: http://www.papalencyclicals.net/.  The official http://www.vatican.va/phome_en.htm houses several documents, but the search interface is more difficult.

Additionally, while not an official source, the Catholic Encyclopedia tends to be a good summary of issues from an informed theological perspective.