I work in Pa. My employer says that since we get paid on an incentive program(meaning, we start at a base rate and the more we do the more we make, up to a certain point), he can make us work O.T. at straight time. If this is true can I see this in writing? Possibly a link to a site.

Not true. The employer must pay Non-Exempt employee minimum wage and overtime. Presumably you are a Non-Exempt employee since there is never a legal obligation to pay an Exempt employee overtime.

One caveat. Minimum wage and overtime is calculated on a work week basis. The total of all payments made for the work week are used to see if the MW and OT requirements are made.

The basic federal OT rules can be found below. If you post more specific information about exactly what type of work you are doing, there might be something more specific available (like say Inside Sales).

I am going to let someone else address any PA specific issues.

http://www.dol.gov/esa/regs/compliance/whd/whdfs23.htm