Data from the National Longitudinal Survey of Youth were analyzed to identify patterns in the early labor market and employment experience of a sample of 12,781 U.S. youths who were first interviewed in 1979 (at ages 14 through 21) and last interviewed in 1990 (at ages 25 through 32 years). School-to-work transition patterns were classified by school-leaving group (SLG) (no high school diploma, high school diploma, some college, college diploma, or some postcollege education). SLGs were analyzed in terms of the following factors: percentage of sample members employed, percentage in school, number of jobs held, and age at entrance into first job. While the median high school graduate entered his "three-year job" while he was 22, the median high school dropout, who first entered the labor force several years earlier, did not enter that job until he was 23. In contrast, the median college graduate--who entered the labor force four years later than the high school graduate--entered his "three-year job" shortly after turning 23. Although racial/ethnic groups and women manifested different employment, school attendance, and job stability patterns, the patterns of school-to-work transition by male high school graduates were surprisingly similarly across the three racial/ethnic groups. By using the SLG classification and a different concept of job duration, the study found less support for the notion that high school graduates typically mill about in the labor market until well into their twenties. It was recommended that school-to-work transition initiatives be targeted toward high school noncompleters. Appended is information about sample distribution by SLG and effect of alternative SLG definitions and/or sample members' return to school. Contains 53 references and 67 tables/figures. (MN)