An analysis of the benefits and costs of public library services. Among the questions addressed are: How should the library allocate its book budget? What kinds of books should it tend to buy? What do library services cost? Who uses the library and why? What are the choices among circulation systems? What is the optimum loan period? Would a security system be worth the price? To maximize usefulness, answers to these questions were structured around the needs of a particular library. A book-selection model was developed to increase the benefits from a given size book budget. Two results obtained from the model were the types of books the library should acquire and an estimate of benefits derived from each relative to cost. Data were provided by user and community surveys. Automated circulation system costs were explored, as was the effect of changing the time books are allowed to circulate. Ways to improve services are suggested.