Re: References/Reference Letter
well - the onus is on the candidates to make sure that the references they are providing will speak in their favour. No one should even mention a reference without having consulted with the potential referee.
The referee’s answer to a simple question like “can I provide your name as a reference?” should give you an indication whether it’s a good or bad idea. I’m usually very open with people who ask for my reference. In a couple of instances, I’ve denied the request when I don’t have anything positive to say… other times, I’ve said neutral things… but 80% of the people who ask me are pretty sure that I’ll say good things about them.
Re: reference letters, it really depends on the job application requirements. In my experience, most mid-level management positions and above would probably request a reference letter as part of the initial application package and also names of references who can be called up after the interview process.