Who knows a good manual for Ubuntu?

Question

linux

I need a concise presentation of the material.

Answer 1

How Linux Works book.
The best Linux book I've ever seen.

Answer 2

Advanced Programming in the UNIX Environment
This is a classic that is revered throughout the world. You will not find better, and, therefore, more concise too.

This is the most worthy second edition of the classic.

Dennis Ritchie Murray Hill, New Jersey, March 2005

Answer 3

It is not very clear what is meant. As shown by the answers above.
It is necessary to read books on Linux (which ones - again, it depends on the goal), and not any kind of mess like which buttons to press in which cases.