Correct way to handle Ajax calls in ASP.Net MVC 3

When coding up Ajax calls in ASP.Net MVC we have a lot of options as far as issuing calls, handling them on the server, and dealing with successes and failures on the client. Some things clearly have a correct answer, but I've been unable to find clear-cut guidance. So, end-to-end, what is the correct way to make an ajax call?

Including

• What is the best way to inject the url of the action for the url into the ajax call?
  


• What are the considerations when choosing JsonBehavior?
  


• What is the best way to handle errors on the server side?
  
  
  
  • Should the client side error() callback be triggered by any errors (ie unexpected OutOfMemoryException), or only by foreseeable errors (ie invalid input)?
    
  
  
  • What is the best way of exporting errors in a way that the error() callback will be triggered.
    
  
  
  • Best way of ensuring the error callback gets the correct status code and response text.
    
  
  
  • Should validation errors result in an Error StatusCode or should they be part of a responding validation object.
    
  
  
  
  


• What is the best way to handle errors on the client side?
  
  
  
  • Should unexpected errors server-side be displayed in a similar way as the validation summary? Maybe a just 'something-went-wrong' dialog? Should the client be able to distinguish between the two?
    
  
  
  
  

Any other things people have strong opinions on?

Source: Tips4all