The purpose of this study was to identify how high school graduate newcomers adjust to working in organizations. This study examines how their formal learning, intended informal learning, and unintended informal learning experiences jointly influence their adjustment processes [e.g., role clarity and personal-organizational (P-O) fit]. It also explores the extent to which the newcomers' adjustment processes relate to socialization outcomes (e.g., job satisfaction, organizational commitment, and intention to quit) and their mediating effects on the relationship between the types of learning and socialization outcomes. Results show that formal learning and intended informal learning have a strong positive relationship with P-O fit, while unintended informal learning is positively associated only with role clarity. In addition, role clarity indirectly and P-O fit directly affect job satisfaction, organizational commitment, and intention to quit. The implication for management practices and future research is discussed.