iCloud does not provide general file storage in the manner of iDisk. You can sync iWork and TextEdit documents to it for access by your iOS devices, and other programs may add this ability later, but as it's intended for syncing to iOS devices (which don't have a Finder-like file structure) general storage isn't possible. For that you will need a third-party alternative: this page examines some options -
Unfortunately, Apple has turned away from the typical 'computer' file system for its cloud solution.
There are many alternative options to file storage online - Dropbox, as you probably have heard.
After Apple's success with iPhone, many things have been more mobile-essentric. This includes iCloud - everything is related to the app. Your app data is stored in the cloud, which allows syncing of data from different instances of the same app.
iCloud focuses on storing App data (Pages, Keynote, Number, Settings, other Apps), Backup (iDevices and their settings), Mail, Contacts, Reminders, Notes, Calender and etc.
Hope that helps, makes a bit more clearer
Definitely look into cloud file storage! A good investment.
Dropbox and Google Drive are the big ones.
My main reason for Dropbox, is that I use it as a backup, aswell as a quick way to share my files.
Everytime you update a file, it saves a version in Dropbox - on your own computer it is still one file.
Dropbox saves these increments for 30days (or you can purchase an addon to extend to lifetime (within the subscription of the addon) - and has saved my life, where I had accidently saved over my original work.