Difference between Simple MVVM Toolkit to MVVM Light Toolkit.

Refer from Tony Sneed's Blog

What is MVVM

Model-View-ViewModel (MVVM). The MVVM pattern allows applications to be divided up into separate layers that provide multiple benefits ranging from better code re-use to enhanced    testing   capabilities.

• "Understanding the MVVM Pattern" (video | source code).
• "Deep Dive MVVM" (video | source code)
• Also, read Josh Smith's article at MSDN
• Shawn Wildermuth's article about MVVM at MSDN.
• Dan Wahlin also has a very good Getting Started with MVVM article.