Did you try to google this?
I got almost 45 000 000 hits. This is a site I have referenced before, they seem to know what they are talking about...
How to Upgrade from Windows 7 to Windows 10 - Windows 10
To be fair you should be ok (Bare metal, vanilla - not UG over the top), that said I expect you know what your doing here and are to that level to understand the following. Or please do not do this, on your head be it !!
Back up all data and configs
Any IE related stuff, books, hyps etc etc
Any software make sure you have licences copys ready or your loose it, once moved to 10 or your loose it and have to re purchase it. Make sure all software is 10 compatible
Drivers for all hardware used and all hard ware you have (do not forget anything)
Make sure all are the right versions of software and drivers x64 etc
Also that you can do back to Win 7 if all fails
Follow the above and anything else you can think of and yoiu should be ok. Any drivers you can not find and save for later after the 10 install - Forget it !! do not go to 10
Sure you get the picture