Windows 10 pre-upgrade check list
There is a good summary and links to more detailed discussion of how to make the upgrade to Windows 10 as trouble free as possible on www.howtogeek.com:
Update to Windows 10 Headache Free With A Pre-Upgrade Checklist
Although millions of people have already jumped on the Windows 10 wagon, there are still millions of upgraders waiting in the wings. If you want your upgrade to be as painless as possible read on as we highlight the best practices for upgrading your PC to Windows 10.