What are some good websites for Win32 SDK programming tutorials?
The best online tutorial with regards to native Win32 programming would have to be The Forger's Win32 API tutorial.
The generally accepted bible for Win32 is the Petzold book:
http://www.amazon.com/Programming-Windows%C2%AE-Fifth-Microsoft/dp/157231995X
It's not online, but worth purchasing if you're serious about Win32, IMHO.
This is my favorite: Win32 Programming by Rector & Newcomer It is massive and goes through all the basic concepts down to the nuts and bolts about Win32 programming.
BTW: Newcomer has a website also with examples (although more related to MFC) here
If you really need a simple starter that will guide you through the basics. You can read "Windows Programming from the Ground Up" by Herbert Schildt. It will be a good forerunner to Charles Petzold. I read Herb Schildt first and then Charles Petzold, and I really was able to understand what Petzold was talking very easily.
Avoid tutorials (by kids for kids)
Read the Petzold + Richter + Adv. Win32 Group (news://nntp.aioe.org/comp.os.ms-windows.programmer.win32)
And avoid Newcomer (newbie in Win32, knows MFC only...)