Why do you want to learn Japanese?
Is it because you're about to travel to Japan? Is it because of any business reasons? Or you're just a fan of Japanese films or manga comics? Whatever the reasons are, your goal should be to learn to read, speak, and understand modern Japanese.
One method that you can use to learn Japanese is through "picture learning" software. In this method you visualize certain Japanese characters with the pronunciation together with its meaning. Some computer software use this approach to build vocabulary in the context of understanding, speaking, reading, and writing Japanese. This system makes the whole process more fun and can have the student mastering hundreds of words in a matter of days. Some software utilize a "game" type approach to reduce boredom, stimulate interest and improve speed of results.
Aside from computer software, you can also use flashcards. They are also considered to be a great way of learning Japanese. If you can't find flashcards at any bookshops or online, you can make them on your own just by cutting some cardboard and writing an English word on one side, then a Japanese translation on the other side. Easy, isn't it?
Japanese is one of the world's major languages, right up there with Mandarin, English, Spanish and French. In fact, businessmen with exporting and importing businesses employ people that know how to speak Japanese to gain more business partners.
What's the best way to learn Japanese?
Learning Japanese in Japan is the best and quickest way to learn the language as you would learn how to speak Japanese just as a native speaks it. Understanding the culture behind the language is a very important part of learning to speak and write Japanese. It is a very difficult language to learn how to write, but if you learn it in Japan you will give yourself a much better chance of learning it properly than if you went to some day or night class in your home city.