This short video has a number of very practical tips for shelving and caring for old/rare books in order to help preserve them. This is great for Dhamma books.
My favorite tip in the video: store your books flush to the wall, instead of with theirs spines flush. This will help keep their covers from warping over time. That was tip # 2 of 8.
Do you have a favorite tip?
And here is a very good comment from the comment section:
"Greetings. Librarian here, worked in a library with a rare books collection, took an introductory course of book conservation and restoration. Observations:
- Shelves. Depending on the climate where you live, untreated wood shelves are preferable to varnished ones and both to metallic ones, to diminish water condensation.
- How to take books out of the shelf. Agreed, with a caveat. If where you live there are spiders of the brown recluse kind, they love to hide behind books. Safer ways to take books are pushing in the books to right and left so you can grasp the book you want, or, using gloves.
- Gloves. Yes, you can read old books without gloves, and if your hands are clean that will not damage them, but, if a book has a mold/fungal infection, it can infect others in your library, and you may get sick from it. Unusual, but you don’t want to be the one in a thousand case. If you have a visibly infected book, treat it with extreme caution - for the sake of the book and yourself."
Happy reading. 
R