When Looking for a Job/Employees

First-- don't expect potential employers to discuss salary with you prior to an interview.

Some questions that I would ask:
1. What is the staff turn-over rate? How long have hygienists, assistants, front-desk personnel been in the practice?
2. If looking for an associateship-- did the hiring dentist have any previous associates? If so, what was the reason for leaving? How long were they there?
3. What procedures are kept in-house? What procedures are referred out?
4. Who are the referring doctors?
5. What labs do you use? Do they have an on-site lab? Do they have samples of work they can show you?
6. How are new patients assigned to dentists? Especially important for new associates. Does the new associate get all new patients, every other new patient, or every third new patient, etc?
7. And when you discuss salary-- is it % collection, % production, guaranteed minimum, monthly draw, etc?

You want to make sure you are not going to be doing all the "grunt" work-- like you get to do all the molar endo while the senior dentist gets to do all the crown and bridge.

These are just a few questions off the top of my head. Hope they help.

The on-site lab is the least important of the things I mentioned, and it was actually something I hadn't thought about until I had an interview at a job that had an on-site lab. The benefits are that you are directly working with the same lab technician for most of your cases. He/she knows how you like things done. If you need a quick turn-around on a case because a patient is going out of town or needs the crown or whatever it is sooner than normal, they could get it done quicker having an on-site lab. If you are delivering a crown and if you need any adjustments like adding porcelain to a light contact or open contact, they can do it for you while the patient is there, rather than telling the patient, "sorry we have to send your crown back to have porcelain added." So it's convenient, as long as they are good. A downside is having your own lab tech will increase the practice overhead, something that is important to consider if you ever own a practice and want your own lab tech.

To your other question:
% collections -- salary based on what money actually collected for the work you do, this is great if the practice is fee-for-service, and it is also great as long as the practice has a good collections rate (i.e. 97-98%+). Some months will be higher, and some lower, but a good collections rate to shoot for in my opinion is around 97-98% on average. I have found from interviews that practices pay a greater % when associate's salary is based on collections. 30% collections seems average from what I have heard, 35% would be great.
% production -- salary based on what you actually bill for, it seems most practices will pay based on production, and it is usually a lower percentage, around 25-28%, 30% production or higher would be great if you could negotiate it
Monthly draw -- this is just an amount of money that the dentist agrees to pay an associate while they are building their patient base in the practice, essentially it's money that has to be paid back to the dentist at some point, but it's something to live off of while you are getting patients, and as a new grad, increasing your speed, because you won't be as fast at the beginning when you are fresh out of school, a monthly draw is a guaranteed amount of money that once you start making more than the monthly draw, the dentist will pay him/herself back with the money he/she has essentially loaned you, and they take this money out of your paycheck before they pay you, so once you start making enough where you don't need the monthly draw anymore, i.e. your % production or % collection is greater than the monthly draw, the dentist will start paying him/herself back before giving you your paycheck
And then there is a guaranteed daily minimum that you will find in corporate or large group practices, and they usually do this for a period of 3-6 months, and this is not typically done in private practice because in corporate you are an employee, but in private practice associates are typically hired as independent contractors