Dictionaries, Encyclopedias & Digital Libraries

• Z-Korean
• Lexilogos
• Wordreference.com
• Naver English dictionary

Grammar

• An Introduction to Korean
  Overview of Korean grammar, vocabulary and pronunciation
• Wikipedia
  Overview of the Korean language

Vocabulary

• Vocabulary Flash Cards
  Interactive vocabulary tests
• English-Korean vocabulary quizzes
  Quizzes ordered by topic
• Learn101 - Korean
  Introductory vocabulary with audio files
• Language Guide
  Basic vocabulary presented as images and sound files

Reading & Writing

• The Korean Script
  Lessons in reading, writing and pronunciation
• How to Study Korean
  Guide to the Korean script
• Quizlet
  Online flashcards for the Korean script
• Hangul Day
  Blog post about the history and structure of Hangul script
• E-library
  Online library created by the Overseas Koreans Foundation

Listening & Speaking

• LearnKorean.com
  Lessons on pronunciation (Real Audio Player required)
• Pathway to spoken Korean
  Materials developed at OSU offering introductory lessons
• Rocketlanguages.com
  Pronunciation lessons with audio files
• Advanced Korean podcast
  Audio lessons for advanced learners of Korean.

Online Course Materials

• Korean 101
  Online video-based Korean course. The 20 lessons focus on reading and writing.
• Talk to Me in Korean
  Award-winning online community offering interactive audio and video lessons from beginning to advanced levels.
• Elementary Korean
  Listening and writing exercises developed by Columbia University
• Intermediate Korean
  Excellent site offering online course materials developed by UC-Berkeley. Interactive exercises offer immediate feedback.
• Sogang University Korean Lessons
  Free beginning- to intermediate-level language lessons offered by Sogang University.
• Foreign Service Institute Korean Headstart
• KPUCP
  16 video lessons for Spanish-speaking learners of Korean

News & Media

• The Chosun Ilbo
  English-language news about Korea
• KBS
  English-language Korean television

Social Media

• University of Iowa Korean Program's Facebook page
• University of Iowa Korean Conversation Group Facebook page

Arts, Films, & Music  

• Hoam Art Museum
  Official site
• Korean Television Shows
  Link to popular Korean dramas
• Korean Pop Music
  News, downloads, MP3s, etc.
• Korean Film
  Introduction to Korean film
• Catchwave
  English-language radio show about Korean popular culture

Tips for Learning Korean Langauge and Culture  

• Optilingo
  This blog curates loads of culture and language learning resources 

Search Engines

• Naver