I've recently added a lot of new info on the Korea hiking blog, including detailed high resolution
printable trail maps of a number of parks, which include
mileage, estimated
hiking times, locations of freshwater
springs,
shelter locations, and
bus stops. All maps were drawn from existing Korean trail maps (provided by KNPS and other sources) combined with my own first-hand knowledge of those parks.
If you hike the parks regularly, definately check it out.
http://koreaclimbs.blogspot.com/
MAPS AND INFO SOON TO BE ADDED:
Seoraksan National Park
Odaesan National Park
Sobaeksan National Park
Taebaeksan Provincial Park