Hi Nicolas,
I got a book from my sister as a present It's called "Climb: 암벽등반"
ISBN: 978-89-958437-2-7
Flipping through the pages, it has great information on public transportation and lodging ideas, etc. But what it lacks is the actual picture with drawn routes on the wall. Most European climbing books have the actual picture or drawing of the wall but this only has a few and those were mostly general pics of multi-pitch routes. It seems like Koreaontherocks has a lot of information and I plan on referring to both.
I think it will probably be possible to find the book at a bookstore like 교보문고 which is a very big bookstore in Korea. I am attaching a link here so maybe you can check it out.
http://www.kyobobook.co.kr/index.laf
I am going to be in Seoul from Oct 3 to Oct 15 with my husband, visiting family and doing some climbing around there as well. Of course, I will bring the book along. If you all want to meet up for a bit and talk about climbing and share information or even go climb together, we are up for it.
HY