I'm rubbish at directions. Luckily, if I want to find some place and I'm not sure how to get there, I can just look it up on Daum 지도 before I go.
If you can read and type Hangeul, and understand the names of places in Korean, just go to daum.net and click on '지도' in the blue menu bar. Voila, you can see a map of Korea and just search in Hangeul for the place you wanna get to. To the far right is a little webcam icon, '로드뷰', which will give you a navigable street view when you click on it and drag the icon to where you want to look. This is the same idea as Google Maps Street View, but personally I find Daum a hundred times better. It covers the whole of South Korea's cities and main roads, including even BOAT routes around a couple of islands, Hallasan's main mountain trail, and the insides of Seoul metro stations.
There are billions of nifty tools on this map service. Buttons on the left allow you to search for bus routes, hotels, and other stuff with one click. A small ruler icon on the far right lets you map a route and it will calculate the distance in metres and the time it would take to walk or cycle. The '스토어뷰' (Store View) actually lets you see INSIDE stores and restaurants. And at the top of the map, you can see how the weather is in the area you're looking at!
Well I hope this information is useful to someone. If you're a foreigner in Korea and savvy enough to read and understand enough Korean to get around, you probably already use this map service. If you don't, I recommend it. In my opinion it does so much more than any other online map service I know of, and is quicker and easier to use than most. I use it to find out how to get from subway stations to mountain trail starting points, to calculate cycle routes and how long it would take me to cycle somewhere, to retrace my steps when I've forgotton where some cool place is and I want to find out how to get there again, and sometimes just to waste time virtually sightseeing around Korea on my computer screen. Thumbs up for Daum.