"Love's Labors Lost" is for the student of Shakespeare, whether in the theatre class or the literature class. It is for actors of Shakespeare, and for the directors. It is a practical guide and an insightful critique. It is also immensely readable.
Granville-Barker is a great, short text for the interested Shakespeare amateur, or even for those of us who think we're professional observers of his work. Granville-Barker walks through the play looking at: 1) the history and context of the work, 2) a detailed synopsis of the play which is structured more as a critical analysis, discussing references, details, thematic issues, and the like, in chronological narrative order; and 3) attitudes toward presenting the play into the modern era.
It's not an all-encompassing work, but it's a great look into the play.