If you are interested in going here are a few tips for you:
To get there by subway, take subway line 4 to Seoul Racecourse Park station, go out exit 2 and follow the crowd down the covered walkway to the track. Races happen most Saturdays and Sundays from 10:30AM to 5:30PM. You can check here for the 2010 schedule.
Here I am in the Seoul Racecourse Park subway station.
The cost is a mere 800 won to get in.
If you are a foreigner, take your passport, and you will be able to get into the foreigner's lounge on the 4th floor. I suck at giving North, South, East, West directions, so when you are standing in front of the building - where they parade the horses before each race:
Now that you have figured it all out, sit back and enjoy the races!
If you want to fit in, dye your hair black and don't wear red...can you find me?