My boss at work needs me to learn Linux. I want to learn it, but I don't know what my goals should be. 1625 Commands is good and their flags used with them.
Basic understandings are good to start out with.
Expose your self a little at a time with a little of everything. Learn a little admin stuff, networking is big of course, security and everything else will follow along. One book that is recommended is the O'Reily's Running Linux 3rd Edition. Basically I need to know how to use Samba, Apache, etc etc. Everything to do with troubleshooting those.