Quick post, just because this is mega easy.
Traditionally, adding dependency injection with any standard injection package to an MVC solution would normally mean that you would have to write a Controller Factory and wire it up in your Application_Start() method.
If you want to add dependency injection into an MVC solution, just add one of the pre-baked nuget packages that does the MVC wire up for you:
It's just much easier - these packages contain code that has done the legwork of wiring up a custom controller factory for you.
Looking specifically at the Ninject.MVC3 package, simply add the NuGet reference. This will add a "NinjectWebCommon.cs" file into your "App_Start" folder:
You can then edit the RegisterServices(IKernel kernel) method to configure your bindings:
private static void RegisterServices(IKernel kernel)