When you first purchase your iPad you automatically get 5 BG of free iCloud storage to use for things like your email, iCloud backups of your devices, your Photo Library, and iCloud Drive. However, items you purchase from any of Apple’s stores like movies, music, apps and books do not count against the free storage totals. If you ever need more iCloud storage you can increase the amount at any time by selecting a new plan that best suits your needs. To do this in iOS 8 go to Settings–> iCloud–>Storage
Here, you will get a snap-shot of your current available storage along with a pathway to manage your storage needs. When you click on manage storage you will see a listing of all your devices that are currently being backed up to iCloud along with how much storage all of your documents and data are currently occupying on your account. You can reduce the amount of storage that is being used by deleting individual documents and data, or by deleting your iPad back-up from iCloud. If neither of those are viable options for you, then change/upgrade your storage plan.
Select–> Change Storage Plan and upgrade to a plan that provides you with the best available option to fit your storage needs. Your current iCloud Storage plan will be displayed along side your options. If you’re like me and you have a legacy plan, once you upgrade, you will no longer have the option to return to that plan in the future. For instance, my legacy plan was provided by Apple as an upgrade once upon a time, and provides me a slight discount that is renewed on a yearly basis instead of the typically offered monthly charges.
Once you make your choice, your existing storage plan will be canceled, and you’ll be charged the prorated cost for your upgrade Your plan is upgraded immediately, and your new monthly payment date is updated to reflect the purchase date for the new plan. You can also choose to cancel or downgrade your plan form your iPad to any monthly storage option that is less than what you are currently using.