Advice for a beginner Linux user

Trying to learn how not to be a casual. Fairly used to Ubuntu and many of the commands necessary to run a Linux distro without a desktop environment (Arch Linux like a boss.) I'm running Windows 7 x64, and I'd like to NOT be. Could anyone recommend a new distro to try out and/or some good things to do or try to be better at not being bad? Any miscellaneous tip would help.

The easiest way to go about it is just to use Linux a lot, particularly the distros that don't hold your hand very much. Slackware is good, Gentoo (if you don't mind waiting for things to compile) is good, I've heard Arch is good but I haven't used it much. Try a BSD. Make friends with a shell (and try different ones), with manpages, and with Google. Don't start X unless you have to. Try to figure things out yourself before reading a HOWTO. RTFM. Avoid step-by-step recipes. Read a good book on UNIX--it's starting to show its age a bit, but Kernighan and Pike's The UNIX Programming Environment is still a great, mostly valid book.