Is this considered taxable income? ?

I am helping someone (person A) sell a product to someone else (person B). It is a business deal between the two people. I'm not sure how or if taxes will be handled between them. That's their business not mine. I will be receiving a share of the money that person A receives. It most likely will be a large sum that the bank will report to the IRS. Is this considered income? If it is income, how should it be reported on my 1040A? Is it commission, non employee compensation, independent contractor? I also will have to give a share of what I receive to another party involved. Am I supposed to tax that person or just give them a check, with me keeping the canceled check as proof that I didn't receive the full amount deposited as income? Thanks for any and all help that you can give me.