For my 30 days of Node I’ve been using a few training resources in order to learn Express. There’s EggHead.io they have great videos, all short and available to download (if you sign up) so you can watch them offline e.g. on the train. Their Getting Started with Express course by Ben Clinkinbeard is fantastic.
I’ve also watched their Introduction to Node: The Fundamentals by Will Button is also a great video series they do.
I’ve also got a few books to read, these are:
There is also a Gitter group which is going to be really helpful. So there’s a few resources, but nothing beats just jumping in and trying to build something and then finding the answers the problems you come across as you go.