iCloud Backup and Restore Overview
How to BackUp
What iCloud Backs Up
This link may be helpful.
and regarding backup of Notes to icloud...
It'll be swapped. When you first connect it to itunes on your computer, you will be given the option to restore from an itunes or icloud backup. I recommend itunes. You can use itunes to make a local backup, but also keep maintaining the icloud backups. Restoring from iTunes is faster, but the icloud backup is added insurance. And if you have photos on the device, be sure to sync them to the computer. Relying on icloud is iffy when it comes to photo backups.
From device to computer...
From computer to device...