I just finished reading Richard Dawkins' latest book today 'The Greatest Show on Earth: The Evidence for Evolution'. It was an excellent read and I highly recommend it to everyone. Whether you already understand evolution, or do not understand it (or don't accept it). The evidence is laid out pretty clearly, and most technical jargon is avoided so even a non-scientific mind can understand the evidence and mechanisms of evolution.
I especially recommend it to you creationists out there.