Hi Everyone! A long time I don't post in here

I have the following issue, I am going to be working with several editors and writers.

The book we're creating has chapters and paragraphs written by several writers, including myself.

And the editors get access to the whole thing, for editing.. naturally.

Could anyone point me to sample Legal contract I could use so that I am sure that:
  • I won't have any legal problems publishing and selling a book that contains their written work
  • They won't be able to use our book drafts without my permission and publish them elsewhere.

I would very much appreciate your help.
I have already begun working with some (they have already written some chapters), and now I am hiring new ones,
so your advice would be needed as soon as possible. Thanks.

Would it be "safe" enough to make them print the contract, sign, scan it, and send it back by digital form, and then have me print, sign the copy, and archive it?

Or would you recommend an electronic signature? Like, I send them the contract in the Email body, and they must reply with their full name, National identitiy number, date and location.

Thanks everyone,
Cheers!
Rod