How do you know if your ghostwriter is proceeding in a timely fashion in writing of your book?
To begin with, you have to have a trusting relationship with the writer. The questioning and the testing ought to happen before you hire your co-author. Once hired, you do best to presume that s/he is working with your best interests in mind until you find out otherwise.
The most effective manner to assure that your project is proceeding along in a timely fashion is to establish a timeline for the project. This ought to be done with the ghostwriter since the ghost writer has a personal process in place which has been honed over the years. You will contribute to this but you are advised to let the ghostwriter take leadership as s/he knows the process well.
You timeline must include all the salient aspects of the project.
1. When will the project be completed? This is an essential first decision as every other decision will depend on it. Make sure this date works for both you and the writer.
2. When will you turn in salient support materials (notes, photos, photocopies, etc.) to the writer.? You may not have these together yet and a deadline for this part of the project will keep you on task for making phone calls or visiting the library, etc. The writer can't start really until these are in hand. Subsequently, when the writer asks for support material, turn them in as soon as possible as the project will be waiting for these.
3. With what frequency will the writer turn in his/her written text to you? This can be every week or every month. It is up to you to decide.
4. When will the project be a quarter done, when half when three quarters? These ought not to be rigid dates but a way of keeping tabs.
Both lean on the writer and actively prompt the writer when it comes to establishing your timelines. In this way your project will not lag and you will not lose your energy.