I pretty use Google Docs to compose everything, so it's always in the cloud with no real need to save. I can type in notes on the app in my phone and write in the same doc on my iPad, laptop, work computer, or any device, really. It can be exported into word docs for easy conversion to Kindle format as well.

Once I'm done editing in Google Docs, I just cut and paste into WdC, pick the ratings and categories, then click save. :)

It's easy to give "suggest" access too, so that others can suggest edits and everything is tracked and each change can easily be approved or declined by the original author. It's really helpful when having others comment or edit.