Rotting,
Welcome to the wonderful world of Linux. Along with the suggestions above, you might try the Ubuntu forums, Ubuntu wiki and how-to's. You will be surprised how much useful information has been accumulated there. When you have that under your belt wander on over to the Gentoo project documentation and forums and/or the Slackware sites.
If you really want to learn about Linux the best way is to jump in. It is a little like swimming. You can study the methods and techniques for the next five years but at the end of the day you will have to actually get in the water over your head to get the full effect.
so as to learn it fully and QUICKLY
I fear if this is your goal you will quickly become disillusioned. Let me tell you why that statement just doesn't apply to Linux. Several years ago my granddaughter got one of those toys, a Transformer I think they called it. You could manipulate it various ways and make 3 or 4 different figures out of it. A child, of course, could intuitively figure it out. Adults could read the instructions and quickly learn to make all 3 or 4 figures. It was designed to make 3 or 4 distinct things. It did what its' manufacturer designed it to do well enough and that's all it would do. It was what it was. That is the Windows world.
There used to be something called Tinker Toys. I guess the more up-to-date version would be Lego sets. They both consist of basic building blocks. You can make a building, a firetruck, a monster, a clown, a merry-go-round, and the list goes on and on. Your imagination is your biggest limitation. This is the Linux world.
To approach Linux as you indicated just doesn't apply. It is a misnomer. It is a goal no one person has ever attained, nor is likely to attain. There is really no limit to what the next person might decide to build with the building blocks that are commonly referred to as Linux.
Good luck,
Fred