Open source is very dedicated to sharing information, comparing and learning, then in this article i will recommend some readings of open books that you can download, read and if you want print freely.
Idealist and revolutionary, Stallman launched the movement “free software” that has shaken the foundations of the entire computer market, representing an inevitable point of comparison for the software producer giants.
Second edition is also available here
The book includes coverage of the following topics: network address translation (NAT), address resolution protocol (ARP), routing, and masquerading. There is a nascent section on bridging, although the focus of the documentation is the use of layer 3 Linux technologies.
Related to distro, choose your favorite:
It’s ideal for those who need vital information on all aspects of using Ubuntu, but who don’t have time to wade through thick documentation.
Each chapter of Ubuntu Pocket Guide and Reference tackles an aspect of Ubuntu.
The manual will help you become familiar with everyday tasks such as surfing the web, listening to music and scanning documents.