Findings from California's Statewide Longitudinal Study (SLS) of community college students are reviewed in terms of their implications for student personnel services. Following a background discussion of counselor functions and training and an overview of current concerns in counseling, guidance, and student placement, the paper examines the inferences of the SLS data and makes recommendations with respect to eight issues. These are: (1) student attrition and retention; (2) differentiated counseling programs for day and evening students; (3) the costs and benefits of student assessment programs; (4) student employment and job placement assistance; (5) in-service education to help academically oriented counselors serve vocationally oriented students; (6) the contributions of the SLS's prototype system for classifying students in a useful manner; (7) the effectiveness of the SLS's sampling techniques; and (8) the improvement of vocational curricula through, for example, different day and evening programs and short-term, skill-oriented courses. Finally, 12 summary recommendations are presented, covering counselor credentialing; further use of student prototype information; methods of computing average daily attendance; open-entry/open-exit courses; fee charges for leisure courses; short-term vocational curricula; different day/evening curricula; and the development of research, articulation, and in-service education models. (KL)