An excellent online source for anyone interested in learning Korean language. A collection of Naver dictionaries lists all kinds of dictionaries to choose from. A very useful feature is the 국어사전 (a dictionary that explains Korean words in Korean) and the 백과사전 (not only explains the words' meanings, but also teaches you about culture, history etc related to the word). For more advanced learners the 한자사전 would be very helpful since it allows you to memorize the meaning of generally two-character words through understanding the meaning of the two components, which makes the process of expanding one's vocabulary much easier.
You'll find two versions of this program available in the VOD section. The ongoing one started on 2/28/05 and is hosted by Beau Jackson and 최현정. Material is geared toward beginning learners.
The previous version of Hello! 안녕하세요 was hosted by Richard Harris and 장은아. It was a bilingual learning experience: Richard spoke in English and 장은아 in Korean. All episodes are still available via VOD.
한국어로 말합시다 is no longer in production, but VODs for all 215 episodes are still available. The entire program is in Korean, so it's not for beginners.
Let's Speak Korean is not for learners who already have some knowledge of Korean. The 30 most recent episodes are available through VOD.