It is very EASY to learn how to ride it!
Here are some guidelines from my own experience:
How to ride the subway
(Bear in mind that this is only for routes inside Seoul city. If you want to go outside Seoul you will need to take another kind of transportation, like the bus)
1. First of all you will need a map of the subway system. Don't be scared of the spider web! With your map find out where you are and where you want to go. Let's say you are in Ewha Womans University (이대) and you want to go to Gangnam(강남). Find both places in the map. In this case both are in the green line or Line 2. Now you know which Line you need to ride, and in this case no need to transfer between lines!
2. Next, you need to pay ofcourse :) You have many options to pay for your ride. There are transportation cards such as U-pass, T-Money which you can charge with money at the subway station in ATM-like machines. These machines explain the procedures in both English and Korean. Other cards are reusable which you can return after you arrive and they refund you 500 won included in the price of the ticket.
3. With your card go to the corresponding turnstile in the direction you are headed. Follow the signs and you'll soon be on the platform waiting for your train! ^^
In case you got lost, don't worry! there are many workers who can direct you on the right way. They are very helpful and kind with foreigners :)
There are other features of the Seoul Metro. It's very clean, even though there are millions of people riding it each day. Everything is well-lit and signs in different languages: Korean, English, Chinese.
Here is a short video of the subway station Line 2. Enjoy the ride !!
