This report provides a step-by-step look at defining, planning, implementing, operating, and supporting Internet services for library patrons. Experts from the Cambridge (Massachusetts) Public Library share their experiences pioneering a high-speed, graphical Internet service that supports the full range of multimedia materials available across the Internet. Their experiences help prepare other libraries for patrons' diverse questions, the support required, and the problems that will be encountered. The guide also looks at the broader context in which library Internet service is evolving--particularly networking efforts by library consortia, by school systems, and by local and state governments. Topics include: determining which services to support; establishing the overall dimensions of an Internet effort that makes sense to each individual library; setting reasonable goals; detailed planning, system design, and budgeting issues; and implementing Internet service and operating that service on an ongoing basis. Appendices include selected handouts from the Cambridge Public Library and a chronology of the Cambridge Project with selected press clippings. Numerous checklists and worksheets, a topical bibliography and resource listing, list of acronyms, and index are provided. (Author/SWC)