I have found MS Project Experts books extremely informative with great explanations and lots of screen captures / diagrams. I bought the Ultimate Study Guide: Foundations – MS Project 2013 and Implementing and Administering MS Project Server 2013. These books have guided me in setting up our MS Project Web Access instance and taught me more about Project 2013/Project Pro. As for classes, I have found some on You Tube to watch and learn from including some from MS. There are also plenty of firms that you can purchase classes from, but I have not pursued that option. I prefer creating my own job aids for my users using our Project Server database because I can merge my understanding with “color” related to how we manage projects and our database. I have done this for years on the various software packages that I have managed. It just takes time, but I think it works best.