You can manually backup you iPad or iPhone to iCloud at any time.
To do this, go to Settings -> iCloud -> Storage & Backup and select Back Up Now.
Manual sync can be useful for doing backups when erasing all content and settings as part of a reset.
Select Manage Storage to see what’s being backed up. Here you can manage multiple devices if you have more than one, and it shows you how much storage space you are using. You get 5GB free to start with. If you want more space, you can buy a storage plan.
When you select a device, you’ll see a list of installed apps. Selecting an app gives you an option to delete app’s backup. You can also switch backup on or off for each app. If you wish to delete the whole backup, you can do that here by selecting Delete Backup.