I always think that learning probability can not only help you to gain more intuition when dealing with scientific relative subjects but also empower you to think the daily life things in a different way. I recommend Introduction of probability [1] since it's easy to study and provides great free video lectures [2].
In my experience, the best part of Meteor is its tightly couple stack so that I can developer very smoothly. But the worst part is also its tightly couple stack when my web/app grows. Really hope that it would be easier to decouple some important package like tracker or minimongo