I made a Visual Studio project template for creating OData services in .Net. Using this makes it quite easy to get started with OData services. It support JSON format out of the box.
It is available at following location:
http://visualstudiogallery.msdn.microsoft.com/902bc0b9-f90d-439d-a23c-a23f5cc25844
Give it a try and let me know your feedbacks.
