Welcome to the Apple Community.
To be able to use documents at iCloud.com, you need at least one iOS device that uses the same account with at least one of the iWork apps installed.
Documents that have been created or edited on your mobile devices and saved in iCloud, can be accessed from your Mac at the website iCloud.com. You will need to download the documents from iCloud in order to edit them on your Mac.
Similarly, any documents created or edited on your Mac, will will need uploading to the iCloud.com website in order for you to share them with your mobile devices.
I like the idea of working with iWork.com files in iCloud.
It makes no sense to work on a file in iCloud, save it in iCloud, and have to manually download a copy of the file to my iMac if I want to have matching files on my computer.
I use Drop Box, and a Time Machine, as backup locations for all my files.
I don't understand why Apple requires a manual step in maintaining duplicate files between iCloud and my iMac.
Drop Box does an excellent job in mirroring my iMac & cloud storage. Now I understand why Steve Jobs attempted to buy Drop Box.
Hope you have access to Drop Box in the UK.
The previous posts were made before mountain lion was released, there is now no longer any need to upload your iWork documents using iCloud.com.
Also dropbox is not a replacement for iCloud in this respect, there is no way to edit documents on a mobile device and put them into your dropbox account to be used on another device.
so if I open a doc in Pages on my Macbook then close it - I can assume it will show up in Pages on the iPad? and vice versa? because it does not. I am signed in to both places with the same iCloud ID. Or do I need to make a small edit and then let it auto-save? or will I get a prompt and option?
A little confused on how it's supposed to work because I see nothing right now. All of the old iWork references in both apps don't help either.
You need to upload copy of pages / numbers / keynote documents to the iCloud account. One option is to use iCloud method to upload / download files - look in upper right hand corner of Safari screen for gear icon. File can then be loaded to your iCloud account. This will open on your iPad if you have iWork software on you iPad. You can open the file and make changes on your iPad which will then update the iCloud file.
Now, if you want an updated copy on your Macbook, you must manually download the file to your Macbook.
It will have a modified name on your Macbook.
So, you could end up with several minor changed versions of the same document no your Macbook. You can think of this as a Macbook version of Time Machine.
I am not going to use iCloud for my iWork documents due to this needed manual step. Will continue to use Dropbox and my Time Machine.
I will only use iCloud for iWork documents if I want to have a mobile version of a file.
As Winston Churchill has also remarked, in Mountain Lion this manual step is no longer necessary, it now all works automatically.
But for non-iWorks files, you still need Dropbox.
And a big bugbear for me is that the iOS and OSX versions of the iWork applications (and especially numbers!) are quite different and the device you work on will strip parts of the functionality away. So the 'work on one document intermittently on an iOS and an OSX device' claim is a lot of bull. Unfortunately. Now THAT's not Apple!