I store my photos in polypropylene bags with magazine backing boards (acid free). I also place a piece of microchamber paper behind each photo.
They are then stored in acid-free archival boxes. Stored flat and not vertical.
You can read about the benefits of microchamber paper here:
http://www.conservationresources.com...croChamber.htm
I don't display my photos, but if I would I would take a hires scan, make a copy, and then frame that for display.