For a website by somebody with a successful track record of language learning, have a look at http://www.alljapaneseallthetime.com/blog/ . As well as a lot of motivation talk (which overlaps LessWrong's akrasia discussion), it focuses on two very important concepts:

1. Learning in real context Rather than isolated words, you should look at whole sentences or paragraphs. These should be from real texts or spoken language aimed at native speakers (start with children's books if you want lower difficulty). Definitions are useful, and Rational_Brony's advice to look them up in the original language is good, but a definition only tells you what a words means, not the subtleties of when to use it. The best way to learn that is exposure to huge quantities of real context.

2. Spaced repetition software This dramatically increases your memorization eficacy, and it works very well for language learning. gwern wrote an excellent article about it which you should read if you're not already familiar with it: http://www.gwern.net/Spaced%20repetition