Some Koreans are quite stocky so there is a good range of sizes. Seoul also caters to American GI's so there is some larger sizes there.
Bring wool socks if you like wool, I haven't been able to find any in Wonju except for one pair of Norwegian hiking socks in a sports shop. Korea makes wonderful cheap, wool and leather gloves and mitts, why they can't figure out how to make wool socks is beyond me! Gr..........! I have not seen much cotton either but it's winter and things are more seasonal here.
I had a really hard time finding long sleeved cotton jerseys (long sleeved T's). I found one store in Wonju that had 3 at a price! This was in October and maybe its a more seasonal thing.
There are lots of coat, vests padded pants, sweat pants, hats and scarves, leather jackets, all at reasonable prices, if you have them, bring them, but don't worry, you can get that stuff here.
If you are tall bring long underwear. I can get some to fit around the middle but woman's sizes are a good 6 inches too short for my liking.
There is great underwear here. If you prefer all cotton bring your own.
Its OK to wear pants here but make sure they are resonable, Jeans are not OK. I
have trouble finding women's pants that are long enough.
Bring deodorant, Koreans don't sweat much and there is none in regular stores. I heard that there is sometimes some in big hotels in Seoul.
Everyone seems to dye their hair but it's hard to find lighter shades. Light brown or blond is rare. Black, dark brown, and reddish brown is common and comparable to western prices. Loreal, wella etc., are all readily available.
You will probably get a cold when you're here so bring over the counter remedies if you use them. They didn't have any Neo citran and it would have felt nice to drug myself and go to bed. Pharmacists will have all kinds of things and they work but it's hard to explain and when you're not feeling up to snuff it's even harder to make the effort. They don't have cough syrup. They have cough capsules. I bought honey to take with my caught pill and it satisfied the urge but Honey is really expensive.
There are vitamins and tonics of every kind. Ginseng is a local specialty, as well as any number of tonic teas.
Sunscreen is hard to come
by. I haven't seen it yet.
Books are also hard to get. Kyobo bookstore has a reasonable selection but nothing out of the ordinary.
One thing you don't really need to bring is teaching manuals. There are lots here. Learning English is a popular activity and there is lots of material.
There is lots of water for sale. It costs about 1000 wons for 2 liters, depending on where you buy.
There is lots of bribing kids with stickers, so it's worth bringing a few with you if you can find some that are fairly cheap. You can get Sandylion brand here but it costs 1500 wons for a small card. There are many local stickers for a fraction of that cost though.
There are electronic cafes and Korea Telecom and the library offers free or cheap access to the net so its not necessary to have your own, I like having easy access (my connection costs 15,000 wons per month plus 500 wons per hour telephone connection cost.)
Get a hotmail or similar
email account, it doesn't cost anything and it's easy to access from any
computer. Tell all your friends and get everyone's address. It's really
nice to get lots of emails.
Wonju is great for riding. The streets are wide enough for a bike and a car, people are used to seeing bikes and there is not too much traffic. Its also only about a 15 minute ride to get out of town. There are lots of great little country roads. I love to ride and its a great way to explore rural Korea. I bought a local mountain bike. It was considered top of the line. It's really sturdy and weight a ton. Otherwise its nice to ride. It set me back about 220,000 wons. It has good brakes, alloy wheels and shimano derailleur, and lots of nice little gears, to handle all the mountains Koreans are so proud of.
There are bikes for as little as 150,000 wons, sturdy 1 speed things with carriers and a good solid look but here are a zillion mountains here so you will want some gears I think.
There are lots of used bikes in shops around town, so I imagine you could get a bike for under 50,000.
If you are tall and need a long seat post bring your own, people are shorter here. If you are a bike snob, then bring your own, there is nothing fancy that I've seen around. Bring a patch kit but don't bring your pump, the tubes here have a different valve so I had to buy a local pump (that weighs a good 10 pounds! and will last a lifetime). Bring your helmet, gloves, and cycling shorts.
There are lots of opticians, as long as you like little oval frames, you're all set. Styles seem a bit limited but not tragically so. You can get contact lens supplies readily.