Preliminary note: rarely, voicemail and text messages are lost after an upgrade. If any of these are important, save them elsewhere before upgrading. (This may require using a Mac and additional software). Contact me if you need help with this.
Steps to Upgrade
- Make sure you have enough space on your device (at least 2 GB free) (see Check the storage on your iPhone, iPad, and iPod touch)
- Check that any old apps you rely upon will work with the new iOS version
- Log into appleid.apple.com to make sure your password works (especially if you have more than one AppleID; for upgrades, you usually log into the AppleID account that you use to make purchases)
- Back up your iPhone or iPad (see How to back up your iPhone, iPad, and iPod touch)
- Run the update through iTunes or over-the-air (see Update the iOS software on your iPhone, iPad, or iPod touch)
- Check that everything (apps, wifi, phone calls, etc.) is working
- Update apps
If you don't have time for all of this, then you don't have time to upgrade.
Learn about iOS 10
Since it will take 30-60 minutes to upgrade your device to iOS 10, I recommend reading about the new features as you wait. A good place to start is iMore’s iOS review. There’s a lot to cover, so you may want to practice with only a few features at a time.
Read This If You Have an Older iPhone
Because of changes in hardware, some parts of iOS 10 don’t work on older devices. The Mac Observer explains what’s missing.
Home Button Changes
If you don’t use TouchID, now is the time to try it again. Apple wants to make the iPhone more useful without requiring anything more than picking up the device—while at the same time keeping most of your data secure. TouchID and iOS 10 is their answer.
The swipe to unlock is gone. You can still use your passcode to unlock, but after the lock screen is visible you’ll tap the home button to bring up the number pad.
Read more abut the home button and other lock screen changes on Six Colors: Getting iOS 10 right from the start.
Messages is the biggest whizz-bang feature in iOS 10, and all the changes can be overwhelming. Six Colors has two articles that are worth checking out: