The purpose of this experimental study is to test a nursing intervention designed to prepare adolescents for the personal coping demands of cancer treatment and to provide them with self-care activities to reduce the negative effects of those treatment demands. The study will use a longitudinal (four measurement points during the first 6 months of treatment), experimental design with one control group and one experimental group. The independent variable will be a structured information-giving intervention that will include didactic, demonstration, and rehearsal learning approaches to increase initiation of self-care strategies designed to promote coping with the demands of cancer treatment. The dependent variables will include psychosocial outcomes and clinical and laboratory findings. Both qualitative and quantitative research methods will be used. Participants will be adolescents between the ages of l2 and 18 years who are patients of St. Jude Children's Research Hospital newly diagnosed with osteosarcoma, or acute lymphocytic leukemia, Ewing's Sarcoma, or Hodgkin's disease, not previously treated, and enrolled on the institutional treatment protocols for those diagnoses. The specific study aims are to: (1) determine the effect of the intervention on selected physical and psychosocial outcomes; (2) test a model of adolescent coping with cancer and its treatment; (3) describe the level of self-care during the first 6 months of treatment; and (4) describe the characteristics of adolescents who report active participation in the self-care strategies and contrast those with the same characteristics of adolescents who deny such participation. Study outcomes will include an intervention that can be readily used in the clinical area and findings that will contribute to a theory of adolescent coping with cancer treatment from which additional interventions could be derived. Findings will also be used to develop similar self-care studies for adolescents diagnosed with cancers that require briefer treatment lengths such as acute myelocytic leukemia and non-Hodgkin's disease, and for adolescents diagnosed with other life-threatening diseases. A subsequent study will address the issue of generalizability of the intervention across treatment settings.