Institutional surveys of student opinion emerged out of the turmoil of the late 1960s. Never intended to serve as professional evaluations, the surveys were the only tangible evidence of teaching effectiveness until some faculty opened their classrooms for observation by chairs and colleagues. Historically, the "peer review of teaching" has typically meant only that a faculty member has watched a colleague lead a class. An observation of an hour in the life of a course yields a letter describing the performance of a teacher, and that letter becomes the peer-review component of the professor's teaching evaluation. Over the past couple of decades, though, the peer review of teaching has evolved significantly. During the 1980s, some faculty members began to assemble teaching portfolios from statements of teaching philosophies, syllabi, descriptions of course intent and content, reports of colleagues' classroom observations, and summaries of student-survey results. This review identifies key resources for the sustainable practice of the peer review of teaching. It focuses on peer review as an expert evaluation of a feature of teaching, such as the depth of understanding demonstrated by students' work or the design of a course. This sense of peer review is akin to judgments made about manuscripts or funding proposals for editors or grant officers. (Contains 29 resources.)