Winlearn is a free tool that will learn .net, VB and even Java applications written with SWT The online help for Winlearn is a good place to start Understanding how to use Winlearn. Worksoft also offers Training classes on using the .Net interface which also covers Winlearn. (Please be sure to let the instructor know that you would like to focus on Winlearn).
Tips and tricks
1. Editing the Window attribute string in WinLearn
2. Using Winlearn to learn a custom menu or toolbar