Sample projects for MVVM Light

Hi,

I've created a project in VS 2012 with MVVM Light(4.5) template.  It comes with few classes and folders.  I was wondering if there are any sample codes or examples on how to customise it for basic needs.

I am struggling to understand ViewModelLocator class, ServiceLocator and SimpleIoc.  I've searched online and understand that the locator is a singleton instance for an entire application and a repository for all viewModels. 

I don't understand do I need to create properties in this class for each viewModel or how does it work ?  Are there any simple but real word examples  - I am just failing to grasp the basics of MVVM Light and it's template.

thanks