One of the new features in VS 2013 is OData Scaffolding. Like MVC Scaffolding, this feature is designed as both a training aid and to speed development. However, it requires a bit more setup than the MVC version. To help you out, Kirthi of Microsoft has created a walk-through on OData Scaffolding.
The most important thing to remember after creating a Web API based OData endpoint is to update the WebApiConfig. By convention, the WebApiConfig is a static class with a single method called Register(HttpConfiguration config). Within this method an ODataConventionModelBuilder is used to actually map the model to an EDM Model. This model is then registered as a route.
If the website was originally created without Web API support you will also need to add this line to the Application_Start event:
GlobalConfiguration.Configure(WebApiConfig.Register);
This method is meant to be used to register routes for the OData controllers and is invoked as a callback to GlobalConfiguration.Configure.