Some good resources if you decide to use VB.NET and the Compact Framework...
www.opennetcf.org - Has a good download section for component libraries and a forum section with many controls and components (including source code).
www.gotdotnet.com - Site run by Microsoft development team that includes code with source as well as How-To articles.
www.intelliprog.com - Has many good articles and How-To's.
Keep in mind that VB.NET is not the VB6 you're familiar with. VB.NET is a fullfledged object-oriented language with many similarities and differences with VB6. Knowledge of object-oriented design and development is not only helpful but essential for effective development in .NET.
One last note: although WM2003 devices come with the Compact Framework installed on ROM, Microsoft has release service pack 1 that includes myriad bug fixes. Many of these devices will still need to have the service pack installed if you want the bug fixes.