Best Way to do Back ups in Windows 8.1

I just bought another hard drive to back up all my files..obviously.

I'm just wondering what the best way to back up the whole drive is. Whether it be the built in Windows software mirroring or a 3rd party clone tool

I would heavily reccomend Acronis.

clonezilla is a good choice as well.

Do either of those do constant backups or do I need to use them manually periodically

Acronis works very well. is a cloud solution that is extremely easy to use and very inexpensive. If you want free, the "System Image Backup" included with Windows8.1 and the File History options are pretty good as well.

I've been trying to find out what exactly file history backs up, but i can't get a clear answer about whether it only does certain files or if it does a complete image

It backs up Libraries, Desktop, Contacts, Favorites, and OneDrive (offline files). It is rather limited.

Another option for you if you like the old fashioned file copy backup is SyncBack. This is a great utility.