Andre Da Costa wrote up two epically awesome tutorials on how to download Windows 10 as an ISO or create a bootable USB drive. They should be required reading for any tech using Windows 10.
- How to download official Windows 10 ISO files
http://answers.microsoft.com/en-us/windows/wiki/windows_10-windows_install/how-to-download-official-windows-10-iso-files/35cde7ec-5b6f-481c-a02d-dadf465df326 - How to install and activate Windows 10 using your Windows 7 or Windows 8 product key
http://answers.microsoft.com/en-us/windows/wiki/windows_10-windows_install/how-to-install-and-activate-windows-10-using-your/d713f9f9-e91f-4ffe-a3c0-7ef9639a0559
Kurt Shintaku's Blog 