If you want to get more creative and spend a tiny bit more $$ you can expand even further on the 3 ring notebook idea. I'm not great at explaining things but I'll give it a shot...
You will need a three ring notebook and 1 clear 8 1/2 x 11 sheet protector plus 1 and 1/2 sheets of 8 1/2 x 11 cardstock for each occasion or year. The sheet protectors can be purchased at Sam's, Costco, an Office Supply place or even
Walmart.
Layer the two sheets of cardstock with the 1/2 sheet on top of the full sheet and line them up at the bottom edge (with both oriented "portrait" style)
Attach the two sheets together at the bottom and the sides leaving the top of the 1/2 sheet open to form a pocket. You can adhere the three sides with glue, double stick tape, scrapbooking adhesive or even colored staples. Label the pocket with the year and/or occasion. Decorate as desired with stickers, fancy papers, ribbons, or let your child do the decorating. Slip the finished pocket into the sheet protector and add your cards.
I also decorate the front of the 3 ring binder as I get the ones that have the clear cover that you can slide an 8 1/2 x 11 sheet inside.
Hope that my directions make sense.
Suz