The purpose of this guide to local history resources in Ontario (Canada) public libraries is to evaluate current trends, problems, and innovations, including the use of new technologies. The guide was developed from a survey of Southern Ontario Library System (SOLS) members; a total of 58 libraries provided information about their local history collections. The survey found that local history and genealogy is an important component of the collections of many Ontario libraries. In most cases, local history is an additional responsibility given to regular reference staff. Inadequate staff time and expertise are the chief factors that limit collection growth. Library cooperation and communication with local historical and genealogical societies has resulted in mutually beneficial projects. Many of the libraries' most useful local history resources are the result of provincial and federal grants. A number of problems were indicated by the survey, including inadequate staffing, lack of space, funds, and equipment, problems related to administration of resources, and theft and natural disasters. Automation and new technologies offer great hope for preserving and expanding access to local history resources; an increasing number of libraries are putting local history catalogs, indexes, and actual resources into machine readable form. Also included in this guide are: a directory of the libraries; a list of libraries (with corresponding page numbers) mentioned in the directory; lists of libraries with collection development policies and gift/donation forms; and a bibliography of library produced descriptive and promotional literature. Appendices provide sample polices and forms. (Contains 17 references.) (AEF)