Theatre Talks LLC

Shakespeare Birthplace Trust

Shakespeare's Life & Times

Link Project Gutenberg: First Folio

Absolute Shakespeare

The First Folio

Hamlet Homepage

Internet Shakespeare Editions

Mr. William Shakespeare and the Internet

Open Source Shakespeare

Shakespeare High

Shakespeare in Europe

Shakespeare Magazine

Shakespeare Online

Shakespeare Resource Center

Shakespeare and His Critics

The Shakespeare Post

Shakespearean Prompt-Books of the 17th Century

Touchstone: Resource for Shakespeare Studies

Let's Make Fun of Hamlet (or Let's Make Hamlet Fun) Site

And...
if we must have one site dealing with the question of authorship:

The Shakespeare Authorship Page