In graduate school, I asked an eminent Shakespeare scholar for recommendations on Shakespeare biographies to consult for my thesis on _Measure for Measure_, and he pointed to this work. After studying modern Shakespeare criticism, it is clear that this is, and has been since the 70s, the seminal biography of the bard. Schoenbaum's biography is a shorter version of his more magisterial volume (Shakespeare: A Documentary Life). I prefer the readability of this 'compact' life, in that it excludes Schoenbaum's sometimes lengthy considerations (in the full version) of critical controversies regarding Shakespeare's life.
What makes this biography so impressive and so esteemed by scholars is its (mainly) objective presentation of the facts surrounding Shakespeare's life. He avoids much of the speculation and even fantasizing of many Shakespeare biographies out there, including Stephen Greenblatt's readable and rewarding imagining. Whereas some scholars eagerly interpret the plays as windows into Shakespeare's life, even using excerpts from the plays as biographical evidence, Schoenbaum tends to present the facts without interpretation.
For those students and teachers of Shakespeare out there looking for a complete and unbiased presentation of the facts of Shakespeare's life, I recommend this biography over all others.
But a word of warning: do not expect a colorful portrait of Shakespeare. Because of the lack of evidence, Shakespeare's life can come across as frustratingly incomplete. If you experience this impression, it is a sign you are reading a dispassionate presentation of the facts. Also, do not expect much interpretation of the plays. Such is the approach of impressionistic biographers, and their biographies, while more readable, involve inferences that tell you more about the biographer than Shakespeare.