Suggest Debian text

[Karl]

About 2 years ago I bought a Microtel computer with Xandros installed.  
It has performed almost flawlessly and has weaned me almost completely 
from Windows.  Since it was an OEM version of Xandros, however, I was 
not provided with a user's manual.  I really want a deeper understanding 
of Linux.  Xandros will sell me the missing user's manual, but I have a 
hunch I can do better.  For example, I would like to know the purpose 
and structure of the zillion files referenced during boot.  I have 
played with a few Bash commands, but I am not very comfortable with 
them.  I have a copy of _/Linux in a Nutshell./_  I think I am looking 
for a basic book on Debian Linux.  I went to www.debian.org, but there 
were too many choices.  What are your suggestions.

Karl