Ask HN: Best Intro to Linux resource?

What is the best way to learn the basics of Linux (specifically CentOS)?

The target audience is comfortable programming in high-level languages (e.g. python) but exclusively uses Windows. The goal is to get them comfortable managing RPMs, writing basic shell scripts, able to trouble-shoot permissions problems independently, etc. It's easy enough to just throw them into it, but a more structured introduction would be helpful.