Even if what contrex posted wasn't explained with the best tact, it is still very true and good advice. The best and cheapest way to learn any operating system is to play with it and research it. I understand that posting on a forum is a type of research and can sometimes be the fastest means, but it will be very extremely difficult to find someone online that will have the time and patience to teach you everything you want to know.
There are, however, thousands of tutorials and books and webpages that have been written to assist in linux education. And I will probably pass on a lot more pointers when you need them just because I'm a nice guy, but am by no means a guru.
