The Cambridge Companion to Shakespeare Studies [Hardcover]

It's not an encyclopedic format, but a collection of essays by a variety of writers, on various study topics, each ending with a list of recommended further reading. Chapters are (I'll use "S" instead of writing out the word "Shakespeare" 17 times!):

The Life of S ... S and the Thought of His Age ... S the Non-Dramatic Poet ... S and the Arts of Language ... Playhouses and Players in the Time of S ... S and the Theatrical Conventions of His Time ... S and the Traditions of Comedy ... S and the Traditions of Tragedy ... S's use of History ... The Transmission of S's Text ... S on the Stage from 1660 to 1900 ... Critical Approaches to S from 1660-1904 ... Twentieth Century Shakespeare Criticism (This is broken down into 3 separate essays, one each on comedies, tragedies, and histories) ... S on the Twentieth Century Stage ... S on Film and Television ... S and new Critical Approaches ... Shakespeare Reference Books.

There is clearly a lot of material on performance, but plenty on other topics, as well. However, if you expect a discussion of authorship controversies you'll be largely disappointed. The various writers pretty much assume that the "Shakespeare canon" is by Shakespeare, but some disputed plays are discussed in the text-transmission chapter. And it has a very basic but good introduction to publication and ownership of plays in Elizabethan times.

The book is 328 pages total, well-indexed, and has some - but not a lot of - illustrations, mostly in the "performance" chapters. Definitely worth getting, for high school-to-college students, with the understanding that for most students, it will be a starting point.