You should also bring over some books, as you can buy English books easily in major cities but other places rely on swapping amongst the ex-pat community. There are some used bookshops in Seoul, but they require some searching out. Planes, trains, buses, and taxi's are all in operation throughout Korea. Planes fly to all major cities within Korea cheaply. Korean Airline and Asiana are the two national carriers.
Trains run to most major cities and to all provinces within Korea.
The cost is about equal to Canadian or US fares in first and second classes, third class is cheaper but a little lacking in creature comforts. Always book ahead as Koreans love to travel around the country and space is limited. Any travel agent can do this, or you can do it in person at the station. There are inner city local buses going most anywhere in country and Express buses that service the larger cities. These buses have two classes neither class has bathrooms for some bizarre reason.