It depends on what you want to do and where you want your career to go longer term, but that's specializing. Realistically, you should start him out learning th

It depends on what you want to do and where you want your career to go longer term, but that's specializing. Realistically, you should start him out learning the entire stack and understanding how different pieces fit together to create a complete picture. Perhaps something like Ruby on Rails that includes a more end-to-end approach. Knowing how the pieces fit together early helps you understand what you enjoy doing and makes understanding future co-workers more expedient.