Give candidate's time - Once you have reviewed CVs and made your selection, give your chosen candidates a couple of days notice so they can make the necessary arrangements to get to the interview.
Explain the interview structure - If there are going to be expected to take tests or bring in examples of their work, don;t forget to tell them so they can come fully prepared.
Explain the process - Even before they meet you, let them know about how long it will take to make the hiring decision and how many stages to the interview there are.