Certain overloads of Controller.View() take a model as a parameter (you can get the full list via IntelliSense, Reflector, or the Object Browser). If you pass a model object into these methods, that object will be available on the ViewData.Model property in your view page. Note that if you want to access your model as a strongly-typed object rather than just an object, you should make your view page inherit from ViewPage<TModel> rather than just ViewPage.
If you tried these and are still experiencing a problem, please post your controller code, view page code, and the error message that you're getting. We'll be able to be of more help if you provide that information.