First question here is are you looking for a job because you don't have one for what ever reason or are you just feeling around to see if the grass is greener?
If you are in need of a job, you probably don't have too many choices and best advise is take what comes your way then feel around for something new.
If you are just feeling around, remember, when you go in, you'll be low man on the ladder. Some questions to ask;
Is the company year round and will the company keep you on daily?
If they are not year round do they allow for you to apply for unemployment benifits?
On rainy/snowy days, will they still call you in or will only upper personel be called in that day due to it being possibly slow?
Is there a probabtion period? Some places have a probation period that allows the employer to see if they actually want you to stay. Sometimes, after the probation period is over, a raise is included.
What is the schedule of raises and when are you qualified to inquire or expect one?
Raises with further education/certifications?
Overtime possibilites?
Paid holidays?
None of the above are too offensive and can be easily answered by any employer. I wouldn't be offended and neither should anyone else. The answers shouldn't be a secret.
Good luck!