We did exactly this in 2012, when we sold everything and hit the road, scanned in photographs, turned music into mp3s, VHS tapes into avis, etc.
Seven and a half years later, these are some of the lessons we've learned:
1. Keep lots of backups. We've had magnetic media fail several times during our trip. I'm fastidious enough to archive our pictures in separate volumes and keep multiple backups (since they're the only mementos of our past and records of our present nomadic life). We've since moved from platter-based hard drives to solid-state drives (SSD) which handle vibration and shocks a lot better. Who knows what the future mediums will be. Embrace new technology and back-up regularly!
2. Consider cloud-based back-up. There are some free services like Google Photo, Dropbox. But if you have *a lot* of media, especially multi-media, you may have to turn to fee-based for larger storage requirements. Unless you're keeping your physical backups in multiple locations, if they're all in one place, you run the risk of losing everything due to theft, natural disaster, etc. Also, having everything online makes it easy to call up on your smartphone or handheld device without attaching hard drives and cables, etc. Which leads me to:
3. Index everything! Keep them organized in folders, try to create meta tags with descriptions, names, dates, locations, etc. When your media archive gets huge, you'll be thankful that you can find photos and other multi-media quickly because you tagged/organized them, instead of trying to remember filenames like DSCN8006.JPG...
4. Back in 2012, we didn't have Spotify/Netflix. I spent an inordinate amount of time ripping cassette tapes, CDs and DVDs. Now, most of my music and movie collection can be found online via streaming services, but if there's anything you have that's obscure or non-mainstream, either rip it or don't throw it away. Even in this age of Big Data, not everything gets archived. So thankful I saved my stash of 80s Canadian New Wave Music!
5. Rip/Scan at the highest resolution available today. I look back at the stuff I ripped a decade ago and I'm a bit let-down that I was too worried about file size, and that I scanned at lower resolutions. I didn't foresee that storage and bandwidth would become so cheap and plentiful. VideoCDs -> DVDs -> Blurays... technology keeps marching on.
Hope this helps, good luck and safe travels on your nomadic journeys. Perhaps we'll run into each other out there!