hey, best of luck with that is you go ahead...
I dont have any direct experience, but I have two close friends that have done the teaching English gig over there, on 2 occassions each. For the most part, the experiences were very positive. My one friend even ended up marrying a Korean girl and they are currently living in Windsor, ON.
I know that if you are teaching English, the schools will usually pay for your flight over, then if you complete your agreed length of service (likely 1 year) they will pay for your flight home too. The schools also supply you with an apartment which you would share with 1 roomate in most cases. I know both of my friends were able to save a fair amount of money as well as travel around during holidays etc. I believe they were located in the suburbs of Seoul on each trip over there. The city has all the amenities of any large world city as well as apparently some rather neglected areas - I remember one friend comparing it to Calcutta. The other friend had one negative experience, it happened shortly after 2 Korean girls had been run over and killed by a US tank. He was mistaken for an American and was spit on by a group of youths. After that he sewed a Canadian and Korean flag onto his pack and had no further problems.
Sorry, I am just giving you anecdotes with not really much detail that might apply to you...
hope it all turns out well!