Yup, Janner is right on the money. I don't know a sku from a skidoo & a rom is a local museum down the road.
But following that guide I had no trouble at all. Hit those 6 wee buttons on your home screen to open the App Drawer & you'll find Asus backup.
It will give you options to back up Apps or Apps & Data, don't let it fool you...the data it refers to is not your data (ie your photos/notes), it is the App Data.
So backup that, then, backup the personal stuff you want to keep...photo's/notes/ebooks/tunes etc. You can put that on sd card (not sure how, we can point you in the right direction...but you can do it through the File Manager with copy & paste functions.) Just remember when you're done, remove the sd card from your device before you factory reset. You can safely eject the sd card by going to Settings/Storage and scrolling to the bottom to get 'unmount or eject external storage'. Not sure what it reads exactly...often this sd card will be shown in the notification window as well. Tap the clock and see if external storage shows at the bottom. You can also unmount there, though sometimes it doesn't show up or is hidden. Don't let it scare ya, android is forgiving and the site is packed full of help.
Also, if you dig your camera and want a brief tour of options, a basic tour is here.