Object Media recommend the following resources.

Books

Code Complete, by Steve McConnell, Microsoft Press. ISBN:1-55615-484-4
The C++ Programming Language, by Bjarne Stroustroup, Addison-Wesley. ISBN:
Effective C++ Second Edition, by Scott Meyers, Addison-Wesley. ISBN:0-201-92488-9
Programming Applications for Microsoft Windows Fourth Edition, by Jeffrey Richter, Microsoft Press. ISBN:1-57231-996-8
Debugging Applications, by John Robbins, Mirosoft Press. ISBN:0-7356-0886-5
Debugging Windows Programs, by Everett N. McKay and Mike Woodring, Developmentor/Addison-Wesley. ISBN:0-201-770238-X
Undocumented Windows NT, by Prasad Dabak, Sandeep Phadke, Milind Borate, M&T Books. ISBN:0-7645-4569-8
Windows NT/2000 Native API Reference, by Gary Nebbett, Macmillan Technical Publishing. ISBN:1-57870-199-6
Undocumented Windows 2000 Secrets, by Sven B. Schreiber, Addison-Wesley. ISBN:0-201-72187-2
Inside Microsoft Windows 2000, Third Edition, by David A. Solomon and Mark E. Russinovich, Microsoft Press. ISBN:0-7356-1021-5
Writing Secure Code 2, by Michael Howard and David LeBlanc, Microsoft Press. ISBN:0-7356-1722-8
Rootkits - subverting the Windows Kernel, by Greg Hogland and James Butler, Addison-Wesley. ISBN:0-321-29431-9

Microsoft Developer Network. The best source of information and SDKs for development with Microsoft operating systems.
System Internals. An excellent source of Windows internals information.
Rootkit.com. Website discussing implementations and implications of rootkit development and rootkit detection for Microsoft operating systems.
Stack Overflow. Software related question and answer website. Well worth a visit.
The Code Project. Simply the best Windows community developer related website. For any-use windows related source code, you can't get better than this.
Software Verification Limited. Superb software tools at excellent prices. We wrote the software tools that Software Verification sell.
The Register. Industry gossip that is often closer to the truth than they realise.
Techdirt. More industry gossip.
Slashdot. Linux based industry gossip. Not as good as it used to be.
User Friendly. Topical industry cartoon.