Following are some websites and links that I found interesting and useful for learning Korean:
http://ling.kgw.tu-berlin.de/Korean/Artikel01/Korean.htm
http://en.wikipedia.org/wiki/Korean_language
http://rki.kbs.co.kr/learn_korean/lessons/e_index.htm
http://www.langintro.com/kintro/
http://www.lifeinkorea.com/Language/korean.cfm
http://www.declan-software.com/korean.htm
http://hangulforest.com/index_e.htm
http://learnkorean.elanguageschool.net
Comments
I really like using Mango for learning Korean as a beginner. It helps me to familiarize and memorize many vocabularies. Also, I has several divisions and each division has a certain topic, including Greetings, Gratitude, and Goodbyes, Names and Introductions, Getting Around, getting help, and etc. There are very specific conversational goals and grammar goals. For me, the most useful parts are Shopping and Payment, Numbers and Currency. It taught me how to count up to 100,000, deal with Korean Currency and Negotiate Basic Transactions at Stores, Ask or Tell Whether One Can Use Something, Ride a Taxi and Pay the Fare.