As you do your research on the employer, you may generate some questions about the position, the company's culture, or career paths within the organization or industry. The response you'll get can give you good insight into what you need to emphasize about your background. In fact, it has been effective in many situations for the applicant to ask early on in the interview what the employer is looking for in an applicant. That way you can volunteer useful and focused information throughout the interview. Early discussions about salary are often a screening device used by employers.
Salary negotiations are much more successfully undertaken after the offer of employment is made.
You'll want to establish the fact that you are the right person for the job first. If pressed by the interviewer, then you may want to ask what range they have budgeted for the position before you mention a figure. It's a good idea to anticipate the question, though. Include this in your research, using salary surveys and other information, to determine the appropriate range and your own value in the specific marketplace. I am planning to go to graduate school in a year or two.