Here is what I will suggest : 1. CSS Preprocessing Language : Any one of LESS or SASS. 2. Twitter Bootstrap or Zurb Foundation. 3. Concepts of UI/UX Design.

Here is what I will suggest : 1. CSS Preprocessing Language : Any one of LESS or SASS. 2. Twitter Bootstrap or Zurb Foundation. 3. Concepts of UI/UX Design. 4. Let him do some projects and hone his skills. How about making his own website/portfolio or making some HTML templates/themes and try selling it on marketplaces like themeforest? 5. Once he becomes good at UI/UX Design & Development he can then focus on back-end. I would suggest him to go with Python & Flask. Learning Python language will not only help him in web application development but it will also allow him to explore & play other interesting stuff like Machine Learning, Computer Vision, etc.