PBS
Pbs Frontline: The Shakespeare Mystery
This site weighs the ever present debate about who really was Shakespeare, and whether or not he truly wrote all he wrote.
Other
Shakespeare Oxford Society: Beginner's Guide to Shakespeare Authorship Problem
This site from the Shakespeare Oxford Society contains a great deal of information in support of the theory that Edwared de Vere, the Earl of Oxford, actually wrote the works traditionally attributed to Shakespeare.
Other
The Shakespeare Authorship Page
This site, by a renowned Shakespeare scholar, systematically refutes arguments made by people who argue that someone other than William Shakespeare, most notably the Earl of Oxford, wrote the works of William Shakespeare.