Following e-books are very useful for newbies to GNU/Linux.
The first one, “GNU/Linux Basics”, describes some of the history behind the development GNU/Linux and the basic architecture of GNU/Linux systems (but no explanation about kernel at all). The second one, “GNU/Linux Advanced Administration” goes somewhat deeper into an administration level. These e-books are completely for beginners and not intended for experienced users. Pdf versions are available at the following links.