Spinal fusion with or without instrumentation often requires the use of bone graft. Bone graft may be autogenous or exogenous. There are various forms of bone graft which may be acquired from numerous sites. Knowledge of fusion biology is imperative for understanding the benefits and limitations of these grafts. Equally as important is the knowledge of outcome measures, management of donor-site morbidity, and potential reconstruction. This review details the methods of obtaining bone graft and details the properties of each, as well as discusses observed outcomes, donor-site morbidities, and reconstruction techniques.