Internet information sources are widespread, websites dedicated to GNU/Linux and its use or configuration are numerous. But websites are not all there is.
MandrakeUser.Org (MUO) is a knowledge base for Linux-Mandrake users. With over 200 pages and growing, it is arguably the biggest collection of Linux-Mandrake related documentation on the web. Apart from the online version of this excellent handbook, that is :-).
MUO collects submissions by Linux-Mandrake users, features a discussion forum and a community newsletter. The articles are targeted at entry-level to semi-advanced users, they not just repeat what you can also read somewhere else, but are rather written in a "hands-on" manner. In short, they work :-).
Topics range from administration issues like handling the shell to tweaking the performance of X, the graphical subsystem of GNU/Linux.
You will find it at MUO
A section of the Linux-Mandrake website is dedicated to a lot of demos and tutorials. You will find among many others demos about the installation, and the graphical environment, tutorials about many aspects of the configuration of your system: network, packages maintenance, server configuration, etc.
Of the multitude of existing websites, here are some of the most exhaustive:
http://www.linux.org/: one of the very first sites dedicated to GNU/Linux, it contains a whole slew of links to other useful sites;
http://freshmeat.net/: if you want the latest applications in the GNU/Linux world, here is where you want to go;
http://www.linux-howto.com/: documentation and more documentation :-)
And of course don't forget your favorite search engine. It is often the most practical tool for finding the information you need. ... A few well chosen keywords in a search engine will often produce answers to your specific problem.
To get help on news, you can, and probably should, first look to see whether your problem has already been covered (or solved) on Dejanews. If you don't find anything, there is a newsgroup entirely dedicated to Linux-Mandrake, and you also have access to many groups in the comp.os.linux.* "hierarchy":
comp.os.linux.setup: questions on GNU/Linux configuration (devices, configuration of applications) and resolution of miscellaneous problems.
comp.os.linux.misc: all that will not fit in another group.
and others...
Before posting to one of these groups, be certain that you have read the available documentation on your subject. New users who post to these groups without proper research are often told nothing more than to RTFM.