iPhone 4s, Contact backup and restoration
Hello, I have an iPhone 4s and I need to restore from factory settings but as a businessman I have tons of contacts on my phone and I can't afford to lose them. They are saved in my iCloud but I worry that if a reset to factory settings, I will lose the data. I am doing this because I need to delete the 9GB of Documents and Data I have because my phone has hardly any space.
So, the task at hand:
1. How do I assure that my contacts will be saved and not lost if I restore my phone from factory settings?
2. Once I restore, how do I put them back on my phone?
3. How do I assure that I don't have such a large buildup of pointless Documents and Data again?
iPhone 4S, iOS 7.0.6