Microsoft
Microsoft.com: Microsoft Windows Home Page
Visit Microsoft's site for information and resources on various Microsoft Windows products. Tips, downloads, product information, plus much more can be found here.
Other
Extremetech.com: A Switcher's Guide to Windows/os X
Now you can run both Mac OS X and Windows XP on the same computer! This article describes how, with an Intel-based Mac and Apple's Boot Camp software, you can explore how the "other half" operates.
Other
Jan's Computer Basics: Trabajo De Jan Con Windows
This site is a step-by-step lesson that guides learners through the basics of using Windows. Covers a few versions of Windows. The tutorial is broken into sections with a practice quiz at the end.