These are resources that I use to learn about Linux/UNIX and often recommend to friends.
NewsGroups:
The two newsgroup that I often read are comp.os.linux.development.system  and comp.os.linux.development.apps.
References
Linux Device Drivers, 2nd Edition     by Alessandro Rubini  &  Jonathan Corbet, O'Reilly     and Associates, 2001.
A thorough description of device drivers development in Linux, including discussion of     many architectures. ISBN:0-59600-008-1
UNIX: Network Programming: Networking APIs     by W. Richard Stevens.   This book introduces virtually every basic TCP and UDP     sockets. ISBN: 0-13-490012-X
Programming Embedded Systems in C and     C++ by Michael Barr, O'Reilly and Associates,     1999. An introduction to the world of embedded system development using C and C++.     ISBN:1-56592-354-5
Online resources
Embedded Systems Programming
A must have for any embedded systems developer. Arcticles cover a wide range of operating     systems and architectures.

Linux Journal

Covers the latest and greatest in the Linux world. Although this particular magazine isn't     aimed at the embedded crowd, it does contain information which is often pertinent to the     future of embedded Linux.

Embedded Linux Journal

Linux Journal's younger brother. This magazine is mainly aimed at embedded system     developers who would like to use Linux in their systems. Contains useful examples and     product reviews.

Dr.Dobb's Journal

Very rich content on all areas of programming. Covers many programming languages and     application fields. The perfect way to keep up to date with the latest in programming.
 



STL information
If you are a C++ programmer and need to STL in your application, SGI has an excellent website about STL.

Assembly programming
Paul Carter's text on assembly is good starting point. There is also  "The Art of  Assembly Language Programming" by  Randal Hyde.

General programming information
I always go
Microsoft MSDN for general C/C++  inquiries. Microsoft gives free access to MSDN on the internet.

DDD Debugger
If you use DDD debugger  to debug Unix applications, you can find DDD tips here.
Copyright 2001-2002 by Peter (Phong) Ho