Once you get the call letter, you are in the second phase of the job acquiring process. Here you need to understand and prepare yourself thoroughly for behavioral interviews, psychometric interviews, technical interviews and so on. You also need to learn in depth about the company you are appearing the job interview for as well as what exactly the job requires of you. Before you appear for the interview you would need to match your skill and strengths as closely as possible to what is required for the job. Also do some research on internet about job salary and employment guidelines for similar kind of positions.