The Scientist and Engineer's Guide to Digital Signal Processing - Complete DSP text book available on-line.
DSP Store - Online store for DSP related products
DSP Net - DSP Web Site
EG3 - Embedded Systems Web Site
. . . . . EG3 DSP Internet Resource List
DSPedia - The excellent DSP CD-ROM
Forward Concepts Home Page
Lots of hot multimedia & code links
Yahoo - Signal and Image Processing
Signal Processing Division - University of Strathclyde
Signal Processing Info. Base
Rice DSP Group
Rice University Signal Processing Software
The Ptolemy Project
Publications of the DSP Design Group & the Ptolemy Project
Berkeley Design Technology, Inc.

DSP Manufacturers :

TI DSP Solutions
Freescale
Agilent
StarCore LLC
Analog Devices Inc.

Other Commercial Organizations

Keil mVision
IAR Embedded Workbench

Trinity Convergence - Purveyors of Voice Over Packet solutions and damn fine chaps
SoftIntegration - C Interpreter And Data Visualizer
Agilent (formerly HP) - Get an evaluation copy of VEE from here
Mathworks - Matlab
Lindquist Systems Group - DSP & filter design services, consulting, R&D, workshops & seminars
Hitex - Suppliers of embedded development tools

Communications Standards

International Telecommunication Union (ITU)
European Telecommunication Standards Institute (ETSI)

Mobile Communications

3GPP
3GPP2

Comp.DSP FAQ
Comp.DSP archive (gopher)
Active Noise Control FAQ
Sci.Image.Processing archive (gopher)
Comp.Speech FAQ - USA

Personal DSP Related Web Pages

Jörgs useful and -=* ugly *=- pages - Useful FFT functions
http://www-ccrma.stanford.edu/~jos/filters/ - Useful filter functions
Phil Karn's Homepage - Useful Comms functions
Jeffrey D. Taft's Online Java Filter Design Tools

DSP & Related Courses

University of Oxford, Summer Engineering Program (UK) -
Digital Signal Processing and Communication Systems courses

Loughborough University, Department of Electronic Engineering (UK) -
Modular MSc in Digital Communication Systems - Offered as a full time or part time modular course

Embedded Systems Conferences (USA and Europe) -
One day introduction to DSP.

Useful Libraries :

wxWidgets - An excellent free portable GUI library.
PortAudio - An excellent free portable Audio I/O library.

General Engineering Links :

- Science search engine
Embedded Systems Programming
EDN Magazine
Dr Dobbs Journal
C/C++ Users Journal
RTC
Wireless Design
American National Standards Institute
International Standards Organization

IEEE Signal Processing Society