Here are some useful resources:
is a podcast with many other available resources.
About dot com
has a good Linux site oriented to new and intermediate users.
is a new Linux magazine that posts useful articles. Magazine issues are made available under a Creative Commons license nine months after publication dates.
There is also a wealth of documentation at The Linux Documentation Project
, most of it oriented towards the command line (GUI tools may vary, because there are many different desktops for Linux; enthusiasts--and LQ users--tend to gravitate to the command line because it is pretty much the same from one distro to another; it is the lowest common denominator of Linux). The one I would particularly recommend is Garrels's Introduction to Linux, which can be found in several formats partway down this page
. I still have a printout of it on my bookshelf.