A good backup strategy for Windows 8 isn't much different from any other system. First and foremost you want your personal data backed up (documents, photos, music, etc). Things that would be difficult or impossible to replace if you lose a hard drive. The OS and applications can be reinstalled, backing those up should be for convenience and not critical.
Creating a system image to an external hard drive is a good place to start. You also want to consider offsite storage of backup data. This can be by having two external drives (one that you store at work or another house) or using an online service (like Crashplan, Carbonite, Mozy, Backblaze, etc). Because having backup just onsite doesn't protect against fire, theft, etc.
Paul Thurrott at WinSupersite has a good write up for Windows 8 Picking a Backup Strategy. Using a backup of your data along with Push Button Reset seems like it would be a quick way to get back up and running.