This is an excellent online resource, featuring a chronology of Chaucer's life, online texts of all the tales (in both the original Middle English and an exceptionally useful modern translation) and notes on social, cultural, and historical contexts that help you understand where Chaucer was coming from.
Professor Jonathan H. Hsy of George Washington University has compiled this hyperlinked chronology of Chaucer's life. Worth noting is the concurrent chronology of world events that took place during Chaucer's lifetime - and thumbnail biographies of the people in Chaucer's orbit.
Luminarium is an online library of medieval literature. Its Chaucer entry has a biography of the poet along with links to his works, quotes, and study materials. You can also browse the pages of Chaucer's contemporaries in order to better understand the world in which he lived and wrote.
As you've probably figured out by now, reading The Canterbury Tales for the first time - especially in Middle English - can be a bit tricky. Fortunately, this website (and Shmoop!) are here to help you out. Focusing on the Tales' "General Prologue," this site walks you through pronunciation, language difficulties, and other challenges to reading Chaucer.
The late Professor Jane Zatta of Southern Illinois University in Edwardsville has left us with the legacy of this amazing online resource. She has insightful commentary on every single Tale, as well as links to commentary on the Middle Ages and other useful items.
Geoffrey Chaucer hath a blog, and it's awesome. A Chaucer fan blogs (in Middle English, of course) about his daily activities in the modern world. A sampling: "Ich wryte this pooste of blog from an 'tavern of halydaye' in Grand Rapids in the realme of Michigan, wherat Kynge Richard and mynselfe haue ordrid 'Step Brethren' on the 'on demaunde.'" Brilliant.