Hi, Flier. Welcome to LQ. There are some tutorials here at LinuxQuestions that you may find helpful. Also, a search of the forums on any subject will turn up threads with lots of useful and helpful information. I've done that often.
As was said previously, http://www.tldp.org/
is a good place to start.There are many resource sites on the web. I use this search page -- http://www.google.com/linux
-- as it usually does not include non Linux results in searches. You may read the statement, "Google is your friend" lots of times while reading in the forums, and it is very true. Google has an excellent search service for Linux information.
You can find books online, also, for example --
There are, of course, many other sites with books and/or other information.
Just search around a bit, you'll find lots of things to read.