1) Everything. Even simple things like pushing codes to repositories took me eons to pick up. Also, programming isnt hard, in fact its easy. The hard part is understanding how to link up everything, front to back and to others such as codetesting, for example with Rspec.
2) I felt sites that promote start-to-end lessons step by step are great. Like codelearn.org. Videos and all are good too but they often target experienced people, so its much more painful to use those.