Honestly, I haven't found a learn German website yet that I'm really happy with. I've done some learning in classes, books, audio tapes, etc., and classes have worked the best for me, albiet slower than I'd like.

If you're looking at websites, one useful site is http://german.about.com. Does a lot of English explanations of German, but not incredibly useful as a self-study tool, just as a reference.

Also, two sites I've found to be invaluable are:
http://dict.leo.org - German English dictionary.
http://www.wordchamp.com/lingua2/Ver...?languageID=17 - German verb conjugations. Really useful when you start learning the past tense, where the verbs (in my opinion) get confusing.

Cheers!

P.S. Um, to give a basis to my comments, I do have that BBC German website bookmarked... just haven't found it that helpful.