This digest explores the life cycle of public libraries, presenting a "life stages" model and highlighting characteristics of each stage. It provides specific advice on what can be done in each stage to energize the library with "stage-appropriate" action. The characteristics that mark the Birth/Infant stage include: driving enthusiasm and effort of an individual or a few individuals; little or no cash support; very limited space; all volunteer effort; absence of structured supervision, management or control; and lack of formal government recognition, charter, or tax-exempt status. The Growth stage is marked by the following characteristics: a governing body of trustees or board members; a mission statement; charter and legal requirements of non-profit status; volunteer effort that is led by a volunteer coordinator or a paraprofessional; funding raised by special events and contributions; increased donations and some purchases of materials; some bibliographic control and implementation of a materials circulation system; relocation of library to larger low cost or donated space. The key features of the Maturity stage are the hiring of paid staff and sharing of resources with other libraries; with the right management, a mature library may be both efficient and effective through vigorous middle age and beyond, if it can change and adapt to changing community expectations. Characteristics in the Decline stage include the following: operations dominated by rules and routines, rather than customer service; unmotivated, burned-out staff; reduced public support and donations; election or appointment of "one issue" trustees; negative publicity; retirement or resignation of key staff; personnel problems; a library facility that is in disrepair; declining circulation, attendance and volunteerism; reduced hours or service. (AEF)