Some basic topics to cover:
1. Your actual job description including clinical and teaching or research responsibilities
2. RVU/patient volume expectations
3. How is your salary funded?
4. What percent of your time will be designated for clinical work?
5. If answer to #4 is < 100%, is the protected time hard funded or are you expected to pull in salary support?
6. Will the institution reimburse you for conference travel/CE/licensure fees/memberships? If so, how much?
It's always helpful to find out how a position came to be in the first place. Maybe you're replacing someone who has moved on. Or maybe a service line or program is expanding to meet demand (an encouraging sign). Or maybe you would be the first in a brand-new position (in which case it's important to make sure that expectations are realistic, they know what a psychologist actually does, etc.). Take time to learn about the history of any job you consider.