This Kids Count Data Book examines trends in the well-being of California's children, focusing on factors influencing young children. This statistical portrait is based on trends in 19 indicators of child well-being in four areas: (1) family economics, including child poverty rate, children receiving TANF, children receiving WIC, fair market rent, infants born to mothers with less than 12 years of education, child care, and child support; (2) health, including prenatal care, low birthweight, infant mortality, teen births, and mothers initiating exclusive breastfeeding; (3) education, including classrooms, student proficiency, and public libraries; (4) safety, including foster care, child abuse, gun injuries and deaths, and motor vehicle injuries and deaths. The data book's introduction details key findings, discusses data interpretation, and makes recommendations. Part 1, the bulk of the report, contains fact sheets for each county and the state, including information on demographics, overall state findings, county rankings, and trends in the above indicators, with data presented by racial/ethnic group. Data explanations and sources follow. Part 2 contains summary tables organized by indicator detailing state and county findings for five additional indicators median yearly income, unemployment, low income children, high school dropout rates, and graduates prepared for college. The data book's findings indicate that 13 California counties have young child poverty rates of 30 percent or higher. Infant mortality has dropped, with continued racial differences. Statewide teen birth rates continue to drop, with significant ethnic group differences. In the most populous counties, at least 40 percent of Head Start-eligible children are not enrolled. (KB)