The result of a study undertaken by the Santiago Library System (SLS) in Orange County, California, in conjunction with the California State Library, this report presents a complete review of various SLS programs, services, and structures with discussions of alternatives, comparative costs, and comparative advantages and disadvantages for each. Following a preface outlining the nature and focus of the study are a description of the Santiago Library System and a review of the concept of a library system. SLS reference services are then evaluated, with analyses of current levels of services, system service priorities, performance objectives, and alternative service delivery systems. Information and referral services are discussed in relation to the system's reference program. Similar analyses are also presented for SLS programs and services pertaining to cooperative lending (i.e., interlibrary loan), the delivery of library materials, special services to minorities and the handicapped, discretionary services, administrative services, citizen involvement, networking, legal structures, and program implementation. Appended are a copy of the letter from SLS to the California State Library requesting assistance with the study, a copy of a memorandum on the scope and intent of the study, and data tables on SLS member libraries and on public library systems throughout California. (JL)