Solved: Drive image backup

I need to back up my computer before upgrading to Windows 10, I do not understand much about computers and do not know what kind of equipment? device? I need to do that. I look at my hard drive and shows that has 688 GB 621 free and 67 used. Can I back up on CD's or DVD's or do I have to buy an external hard drive? an USB drive? I do not know how much space is in any of those devices and if they can be used. I have a Toshiba Satellite P75-A7200 PC. How long will it take to do the back up? do I have to do it overnight?

I appreciate any assistance.:(