I imagine starting salary is going to vary greatly by geography. Keep in mind that I was working in New York City where all RNs pretty much make more than the national average. I have found that the tools at Welcome to Salary.com! - Salary.com have been pretty accurate. In 2008, my starting salary was $70K, with a fixed raise each year and a cap of 90K. (Also, this was position was salaried, so no overtime and I often worked 45 hours a week.) I had nice benefits, too, so that counts for something.
In the future, I would recommend asking around if you have friends who work in similar environments so you can get a sense of what is competitive. Clinic salaries are usually lower than hospitals, and also less formulaic (hospitals usually offer a base rate, plus x for experience, plus night differential, plus bonus for certifications or MSN, etc.). Use Job Search | one search. all jobs. Indeed.com or Find Jobs. Build a Better Career. Find Your Calling. | Monster.com or even Craigslist to browse similar positions and see if they post the salary. Maybe I'm wrong, but I think in nursing typically a salary is a salary, and it's not really negotiable unless merit based. So I wouldn't sweat it about salary requirements.