I assume that you are thinking of getting a TESOL or TEFL certificate, so I'll give you some advice:

1. Make sure it's from a good program IF you lay down your money for a course. A 'good program'
is 120 total hours / 6 OBSERVED teaching hours. Forget the 'TESOL by mail for only $199.95' shams you see on the internet.

2. Some schools in Korea offer FREE TESOL training. Look for them on the internet. They're out there. Most of the schools in SK don't even require a cert, though, so you'll be fine IF you have a bachelor's degree.

3. If you want to 'test drive' TEFL teaching first, fly to Bangkok, Thailand and get a fake TESOL certificate made in an area called Koh Sahrn Road. This will run you about 3700 Baht (about 85 USD) at the vendor near the Himilayan Kitchen restaurant. If you've never done the TEFL thing before, I highly recommend you go this route. You may jump in, drop 1600 USD on a cert, then find you don't like teaching after all and want that 1600 back (like I want MINE back). You can learn in a weekend in a hotel room what you need to know for the classroom during your 'test drive' phase. After getting the fake you can get a job in Thailand or go elsewhere. I'd go elsewhere, as you'll make more money, get reimbursed for your airfare at schools in many countries, and you'll get a ticket back home when it's all over.

If you DO like TESOL, you can always go for a cert later.

It's all up to you.

Good luck!