Fermat's Last Theorem was the subject of a Horizon documentary, which is available on BBC iplayer.
The Clay Mathematics Institute Millenium Prize page on the unsolved conjecture of Birch and Swinnerton-Dyer gives a complete description of the problem.
Andrew Wiles was recently awarded the Abel Prize for solving Fermat's Last Theorem.
Triples and Quadruples is an article by Plus Magazine, linking Pythagoras to Fermat.
The book Fermat's Last Theorem by Simon Singh gives a history of the problem and sketches the journey of mathematical discovery to get to a proof.