Do learn about Korean, its people, its culture and its history as much as you can, before you actually go there. This way you will not be a total stranger to the people and the land, and what you see or hear will not shock you anymore, because you have had an early knowledge of those things, anyway.
Try to learn some Korean language, especially those things that you will need in your first meetings, like the "Basic greetings, polite words, how to ask something, etc."
In every occasion, especially in the gatherings, parties, or even during the office works, try to observe what others are doing and follow; in order to lessen your misunderstanding with the local people, and not to offend their culture or customs.
Try to accept the fact that their cultural practices are unique, and try to understand them as who they are. Remember that if you were born in Korea, you would also learn to do, as they have learned to do, for thousands of years - so, understanding is the best way of accepting the reality.