Find a lawyer for the product team; not your corporate counsel, but someone whose sole responsibility is advising you on your contracts and recordkeeping requirements. From the sound of it someone who has experience in the publishing industry who has both written contracts and litigated disputes involving revenue sharing.
> What sort of contracts?
I'm not sure how to answer this. It's basically an agreement saying we'll pay the authors X% of the proceeds from book sales every month.
We are a Delaware C corp.