As part of a multi-faceted effort, the National Early Head Start Research and Evaluation project examined the nature and extent of implementation in key program areas and the quality of crucial child development services in 17 research programs funded early in the initiative. Implementation data were collected through three rounds of site visits, surveys of program staff in Fall of 1997 and 1999, and observations in Early Head Start and community centers. This report describes lessons from the implementation analysis of the experiences of the 17 research programs as they developed between their initial funding in 1995 or 1996 and the final site visits in Fall of 1999. Findings are presented regarding the evolving program approaches, progress in overall implementation, variation in implementation, family engagement, service needs and use, quality of child development services, and state development and management. Ten themes summarized the key experiences of these early-funded programs: (1) increased attention to the revised Head Start Program Performance Standards; (2) expanding services; (3) increasing service intensity; (4) increasing child development focus; (5) refocusing efforts to improve child care quality; (6) enhancing family participation in program services; (7) provision of training and technical assistance; (8) evolving community partnerships; (9) changing leadership; and (10) increasing complexity. Selected major accomplishments include full implementation for 75 percent of the research programs, growth of a training and technical assistance system to support Early Head Start, and sustained high ratings of staff satisfaction and commitment. Important challenges include finding effective strategies for engaging families in parenting education and group socialization, increasing father involvement, and balancing program and staff needs. The report's three appendices include indicator checklists, implementation rating scales, and a paper on one program's Early Head Start outcomes in staff development. (Contains 32 references.) (KB)