How to keep your collection
The main rules to follow are basically 3:
Darkness, Air, Humidity
Darkness: keep your collection away from direct sun light or lamps that get hot high. If you can, keep them in dark corridor of your house or in your cellar and take them out of the bookshelf only if you have to.
Air: the paper of a book needs air, because it is made from a tree or rice or other materials which were “alive”. You can also periodically browse the pages. It helps against mold.
Humidity: you should keep the humidity of your personal library around 65-75%. If you live in a dry place and you possess some invaluable works, you might consider to buy a humidifier.
Rice paper can be easily damaged by bookworms and mold, to prevent this I use to leave these books in a cardboard box with camphor in powder. Wrap your collection in newspaper sheets can help to avoid the damage because this type of paper is rich of lead, a metal toxic to bookworms and other insects.