DirectX

BCB-Tools.com
Creates the TDx_Library, a series of easy to use Borland C++ Builder components which translate and integrate entire sections of DirectX into native VCL components, supplying RAD DirectX toolsets. [Commercial]
http://bcb-tools.com/

Chilkat DirectX C++ Game Development Library
Provides a framework and C++ classes for developing DirectX applications. [Open source]
http://www.chilkatsoft.com/ChilkatDx/

The Code Project
A programming site with a large section on DirectX. Includes articles, and links.
http://www.codeproject.com/

DirectX 6.0 and Windows Media Technologies Bring Multimedia to Windows CE
Article about DirectX on Windows CE-based devices such as the Sega Dreamcast console.
http://www.microsoft.com/msj/0799/directx/directx.aspx

DirectX eXperience
DirectX site with articles, tips and tricks, and a list of related books.
http://www.geocities.com/SiliconValley/Way/3390/

GameDev.net
Gives news and contains articles about DirectX.
http://www.gamedev.net/

Games Programming with DirectX 8 and C++
Help programmers who are new to DirectX get acquainted with the libraries, in particular DirectDraw and DirectInput.
http://www.cpp-home.com/tutorial.php?23_1

Got Dot Net DirectX Resource Center
A DirectX section of Microsoft community site. Using DirectX at .NET platform.
http://www.gotdotnet.com/team/directx/

Inside DirectX
Microsoft's authoritative book written by partners on the DirectX team contains many essential details for DirectDraw programming.
http://www.amazon.com/exec/obidos/ASIN/1572316969

Microsoft DirectX Developer Center
Microsoft's official home site about DirectX.
http://msdn2.microsoft.com/en-us/xna/aa937781.aspx

Microsoft DirectX Downloads
Developers can download DirectX technologies, including DirectX 6.0, the DirectPlay 5.0A update, and other multimedia development tools and information.
http://www.microsoft.com/windows/directx/default.mspx

Mr.Snow DirectX8 Column Gold
DirectX programming tutorial collection. [Commercial and free versions]
http://www.xdev.ru/dxgp/rgd_articles_e.asp?s=columns&art=mrsdx8_0000

TripleBuffer Software
Contains DirectX tutorials, source code, and projects for both C++ and C#.
http://triplebuffer.devmaster.net/

The X Zone
Technical articles, FAQ, samples, links.
http://www.mvps.org/directx/

The ZBuffer
A collection of news, resources and tutorials for Managed DirectX.
http://www.thezbuffer.com