American Nurses Association, Association of Pain Management Nursing, American Academy of Nurse Practitioners are great places to start looking. Most pain clinics I know work a basic M-F, hours are varied we start at 7 AM and end at 2 PM and only a half a day on Wednesday, but others I know start at 8 AM and end at 3 PM. We do not work holidays or week-ends.
The FNP that I had working here (she went back to family practice her back ground, now we have a PA) was paid more than she was in the family practice area. Again I believe I have the best job in the whole nursing world working with a provider that treats his staff better than family, he learned early in his practice that nurses can make or break you.
Remember we deal with chronic pain and sometimes people gets this confused with acute pain problems. Hope this helps, if I can help you any more just let me know. Good luck in school, Maggie