making contract with someone else

I have my own little book publishing business that I have stated, and I am now to a point where I need to make a contract with a translator who has translated an ancient work.  I want him to receive 100% of the royalties but I am the editor and the one who will have Createspace print it.  Basically he is the one who receives the benefits while I do the work.  But he wants a contract made up, and I am looking into what it takes to make up a contract.  I am completely new at this and need to know if I can make up the contract agreement?  And once its signed by us, then I really need to know it if gets turned in somewhere, or do I simply make him a copy and me a copy and just keep it filed away?  Thank you!