I am exploring engaging a Ghost writer to partner with me on the development of a non-fiction (well, mostly) business book.
What are the critical elements of the agreement that need to be included?
There are a lot of factors that come up and should be negotiated at the beginning.
You can structure your agreement for a flat fee (most common) or for a percentage of royalties (less common), or a combination.
Regardless of the payment arrangement, you'll also have to decide on certain legal/copyright and process issues:
Hope this helps.
IANAL, but he is. This should be a good starting point.
If you also want to have a look at the ghostwriter side, visit some internet sites offering this service and read their conditions (e.g. the Penn Group; first Google hit, I know nothing about them).
(While looking up services, I stumbled over this link. I do not understand its content, but maybe it is useful to you.)
I think you should identify what your goals are and start from there. You should decide just what the ghost writer's responsibilities are and also identify a means of determining whether or not those responsibilities were met.