Just in Case You Have not Read Chesterton
Nearly all the work of GK Chesterton is in the public domain, and therefore available to read on the Internet, if you cannot bestir yourself to go to your local library. A convenient place to start to find his works is here: http://www.cse.dmu.ac.uk/~mward/gkc/books/index.html
What to read first? I have no ability to restrict myself to one recommendation.
ORTHODOXY — because it is a lively an entertaining autobiographic look at the Christian faith, of interest to skeptics and believers alike (as I can personally attest, having read it first as one, then as the other).
MAN WHO WAS THURSDAY — because it is as odd as you can get without being actually science fiction. It reminds me of those English tv shows, like THE PRISONER or THE AVENGERS where increasing levels of oddness intrude into the read world. Worth reading merely to meet such individuals as the poet of the law, the philosophical policeman, the supreme council of anarchists, or the man in the dark room who hires secret agents whose only qualifications sought is a willingness to die.
I will also recommend THE NAPOLEON OF NOTTING HILL for similar reasons. Reading of the epic adventure of a rather drab corner of London in the far off future days of 1984 (the book was penned in 1904) is quite astonishing. You will never look at streetlamps or watertowers the same way again.
THE EVERLASTING MAN — Chesterton’s work of apologetics, the one that influenced such men as CS Lewis. A masterpiece.
I would also hasten to add THE INCREDULITY OF FATHER BROWN — because nothing is better than a good murder mystery.
THE BALLAD OF THE WHITE HORSE — if your taste runs to epic poetry rather than to murder mysteries.
I might also recommend his biography of St. Francis or St. Aquinas, if your taste runs to biography.