Agree with Saab - CD non rewritable stored properly
Also - Get good quality branded CDs and make 2 copies, 1 each on CDs from different sources and brands (you don't want to find you had a bad batch!). Before storing check that your files pictures etc are all readable on a different computer than the one you made them on. Keep one copy and store the other in a remote location (fire/burglary). Periodically check they will both still read properly.
And as Saab said keep up to date with new media/formats
Finally if you are scanning photos, index file and keep the negatives, they are known to last for decades and better quality scans may be available in the future.
That may seem a bit over the top but if your data is worth keeping 10 years or more it ought to be worth the effort.
DS