Today, April 23rd, is the date most associated with William Shakespeare since it was on April 23rd 1616 when the great English bard died and it was also on this date, April 23rd, that most literary historians guesstimate that he was born in 1564 in Stratford-upon-Avon. You see, records prove that he was baptized on April 26th of that year - typically then two or three days after a child's birth -- so the agreed upon guessed date of Shakespeare's birth date is April 23rd -- also the date celebrated in Britain as St. George's Day.
William Shakespeare was a most prolific writer, who penned thirty eight plays, including the likes of Hamlet and Macbeth, four times that number of sonnets, plus numerous poems, including two long narrative works or poetry. In fact, he was so prolific that there has oft been speculation that he didn't even author all of his own work -- but personally I suspect that those rumors were perpetuated by jealous playa haters of the time. (remember they spread the same rumors about Bob Dylan). But more importantly, William Shakespeare, whose work has been translated into virtually every living language around the world, has also had his plays performed more times than any other playwright in history.
For more on Shakespeare online there are countless sites meticulously dedicated to the man's work including the AbsoluteShakespeare.com and PlayShakespeare.com, which has a lot of great information and links, with each and every Shakespeare play detailed and including forum discussions linked to each. There are also approximately 250 versions of Shakespeare's plays that were made into movies over the last eighty years -- a number of which are on DVD and available at Amoeba Music (ask if you cannot find) including the modernized setting, 1996 Baz Luhrman directed William Shakespeare's Romeo and Juliet starring a very young looking Claire Danes and Leonardo Di Caprio (see clip below of Act III, Scene I):