It's easy to start using ASP.NET Web Matrix to build Web applications.  Take the Tour and build your first application as you learn about ASP.NET and the Web Matrix tool.

ASP.NET Web Matrix Guided Tour

Working with code samples is another great way to get started.  There are also hundreds of ASP.NET samples available, as well as several complete, end-to-end ASP.NET applications. 

QuickStart Tutorials 
End to End Samples 

There are many excellent resources for answers to your ASP.NET and Web Matrix questions, including many you can access online right now! 

Books
Read the Online Book from Wrox Press, "Inside ASP.NET Web Matrix." 
See a complete list of ASP.NET books

Forums
ASP.NET forums on www.asp.net

Tip!  You can search the ASP.NET forums from inside ASP.NET Web Matrix.  Just type a question in the Keyword Search box in the upper right! 

Community Site
www.asp.net, supported by the community and the ASP.NET team.

.NET Framework Help
.NET Framework SDK Documentation

Check online for new releases, known issues and general information about ASP.NET Web Matrix releases.

ASP.NET Web Matrix Release Notes