I need to reset my samsung s3 to factory default

[AC Question]

What is the quickest and easiest way to backup pictures and contacts before resetting

 

[B. Diddy]

Welcome to Android Central! Are your contacts saved to your Google account, your Samsung account, or the local Phone account? If they're saved to your Google account, then they're already automatically synced with your Google cloud.

I suggest backing up all of your photos to Google Photos: https://support.google.com/photos/answer/6193313?hl=en