Based on the experiences and design of a model demonstration program, the guide describes basic considerations in developing services for mildly and moderately developmentally handicapped young children in a mainstreamed, multicultural/bilingual day care setting. Un Bien Comienzo (UBC), a program developed to respond to the needs of Spanish speaking parents with young, developmentally delayed children, is part of Rosemount Center (Washington, D.C.), a bilingual, multicultural day care center for children 6 weeks to 5 years of age. Both assessment and intervention services are bilingual. Intervention by specialists is provided on-site at the day care center when parents cannot leave work to take their children for treatment. Chapter 1 of the manual discusses initial steps in program development, including such topics as needs assessment, funding, setting program goals, and recruitment and advertising. The second chapter describes UBC assessment and intervention procedures, while Chapter 3 focuses on staffing considerations. Staff development and elements of a parent program are discussed in Chapters 4 and 5, respectively. A final chapter is devoted to the ongoing evaluation process and procedures developed by UBC. Sample forms and questionnaires are included in the appendices. (JW)