Oh, and I forgot, you MUST do a little research on the company and ask good questions!! My favorite is, "Six months from now, how will you know you've hired the right person?" and "What would be my first priority in this position?"
Do NOT ask questions about salary or benefits during a first interview. Remember, they are interviewing you but you are also interviewing them, so ask about the culture of the company, how often employees meet, or how departments communicate with each other. They want an employee who wants to work for THEIR company, not one who just wants a job.
Trust me on these things, I'm a recruiter!