I am writing a photo journal (book) on my desktop Mac. I want to import it onto my laptop and save it all in iCloud. How do I get what I have completed so far from iPhoto on my desktop computer to my laptop?
It would be good to know which software you are using to write and maybe even which model your Macs are and the installed OS X versions.
Anyway, as Oron pointed out not all software is compatible with iCloud. There is a way around this by manually managing those files:
When you enable iCloud Documents & Data a folder called "Mobile Documents" is created within your users Library folder "~/Library/Documents". Technically you should be able to use this folder like Dropbox. However, Apple can always make changes to that which may effect that usage.
Dropbox is probably a good keyword here, as it is intended to synchronize your data across devices. So that would be another solution for what you want to do.
Another one (without iCloud) would be AirDrop, assuming your devices support it. Both devices need to be on the same network, wired or wireless (WiFi has to be enabled but not connected for AirDrop to work).
Can you just clarify to us which software you are using to write your book? Not all software is compatible with iCloud!