I have made various half-assed attempts to learn Korean in the past, but somehow my motivation always fizzled out. Then a few months ago, I realized my daughter was much more interested in learning Korean when I studied along with her. I haven't found a class nearby, although I hope to enroll in one when we move into L.A. this summer. In the meantime, I've learned hangeul, and I've been watching lots of Kdramas for listening comprehension practice.
There are so many free resources for learning Korean on the Internet right now. You can watch Kdramas with English subtitles at My Soju, Vikii and Drama Fever.(Alas, most Kdramas aren't really suitable for children, although I did teach my daughter the 3 Bears song from Full House.) There's an amazing collection of vocabulary slideshows on Youtube produced by Korean Class 101. Here's one that teaches the colors:
This video helped me learn Korean phonics and pronunciation.
We've also used this series with my daughter. I recommend it, with a couple of caveats. 1) It's all in Korean, even the menu, and 2) it's a teeny bit annoying after a while. But it's well-designed and engaging for very young kids.
If you know of any other materials or Internet resources, I'd love to hear about them.