icloud is for syncing and backing up data and content on your ipad. For example, I sync my contacts, calendars, mail, notes, documents and photos between my ipad, imac, macbook and ipod. Any calendar entry, document or photo I create on my ipad, will show up on all my other devices with out any effort on my part(once its all set up).
I also have my the content on my ipad and ipod backed up to icloud everyday, automatically. (you get 5gb of free storage, but can purchase more if necessary).
I prefer to use icloud over itunes on a computer, primarily because I don't have to think about it. It works great for me. However, I do periodically backup my devices to my macbook just to make sure I have another backup of my data.
If you can explain a little more about what you're trying to do, maybe I can be of more help other than just posting a bunch of article links.
But here's some more.
http://www.apple.com/support/ipad/
http://www.apple.com/support/icloud/
..and this
iCloud Support
http://www.apple.com/support/icloud/
How to set up iCloud on all your devices
http://www.apple.com/icloud/setup/
iCloud: Managing your iCloud Storage
http://support.apple.com/kb/HT4847
iCloud: Manage or buy more iCloud Storage.
http://support.apple.com/kb/PH2615
iOS: Transferring info from old device to new
http://support.apple.com/kb/HT2109