How To Find Testimonials for my product?

Well, as in, how do I hire people to help me do a voice-testimonial or video testimonial?

And how much do you usually pay them for this?

it depends on what age group and what accent of testimonial you require. usually you can get around $30 each. I suggest to post a project on Geatafreelancer.com.

Depends what product you are offering and how good it is. I had a product targetted at webmasters and swapped free use of the product for a video testimonial. They were really good to. That was over at WF and they love that shit over there