As a part time employee you have full medical, dental, and vision insurance. Your benefits will begin on the first day of the fifth month of employment, (Provided you have reached seniority). You reach senirity on your 31st day of employment. There are no out of check costs for your insurance benefits, but you will probably have to pay a co-payment when you use your benefits, usually $20 per visit for normal doctors visits. Emergency services are more. You also have Prescriiption insurance, but I believe most of those plans are, you pay first and get reimbursed.
The only payroll deductions are the standard government deductions, and if you decide, Union Dues. If you are in a right-to-work state, you are not required to be in the union. Otherwise, I believe union dues are $20 per month. If I am wrong on the amount, I'm sure someone will correct me in a few minutes.
Good Luck and work Safe.