Websites
The title says it all.
The internet archive Representative Poetry Online features the complete texts of all of Shakespeare's sonnets. Handy!
They're all there. Count 'em.
Video
Sonnet 75 appears before your very eyes!
Check out a very dramatic reading.
Here's a version of Sonnet 75, put to music.
Audio
Listen to audio recordings of all of Shakespeare's Sonnets, bundled in 10-sonnet units.
Here's a very accomplished reading, but don't get caught in a staring contest with Big Willy. He'll win. He always does.
Images
This website shows the so-called "Sanders Portrait," which some people believe may be a portrait of Shakespeare painted during his lifetime. (Why do you think he's smiling?) The website also features some other images of the poet, and discussions about which, if any, may show his true appearance.
This painting by the Renaissance-era Flemish painter Jan Provost shows that people back in those days didn't think too kindly of misers. (Take that, skull-face.) It looks like the speaker's description of himself in Sonnet 75 might not be all that flattering—in case you hadn't figured that out already.
Historical Documents
Scroll down to get an image of the first edition of the Sonnets, along with a discussion of its mysterious dedication. You won't find this on Amazon!
This site has the deets on Shakespeare's will.
Books
This accessible poem-by-poem commentary by one of America's leading poetry critics is essential reading on Shakespeare's Sonnets. Shmoop recommended.
This volume and its vast commentary is the most detailed attempt to come to grips with (nearly) every single word in Shakespeare's sonnet collection.
The world-famous author of A Clockwork Orange takes on the mystery of Shakespeare's love life, via this fictional imagining of the life behind the sonnets.
Movies & TV
Now this is interesting. Here's a documentary that follows a group of New York acting students as they explore 15 of Shakespeare's sonnets.
This documentary film tells the story of a newly discovered portrait thought to be the only portrait of Shakespeare painted from life.