Although I'm generally happy here in Korea (due mostly to my job situation being such a good one. Ie: getting paid in full/on-time, nice housing, respect from my bosses, no micro-managing, health insurance/pension being legit), it can be a tough place for newbies working at sketchy hagwons or dealing with public school co-teachers and sometimes shoddy housing. I had a rough time in my first year in Korea for sure. Anyway, if you need a dose of reality as to why Korea is not necessarily a land overflowing with kimchi and dwenjang, check out this site:
Top 5 Reasons to NOT Teach ESL in Korea
However, don't just take my word for it. Check out some other teacher's stories and advice.
Prisoner of Wonderland
A-Z of Teaching in South Korea
And of course, check out The Top 5 Reasons to Teach ESL In Korea for a balanced view of things.