I have been learning japanese for some months now. And while I advise people to learn in classes, if you are interested, there are some free online resources you can use.
You should start to learn the two main alphabets of the japanese language: Hiragana and Katakana. The University of Michigan has a very valuable resource to learn them. I would advise you to write them often until you memorize them. Its a lot of work, but you can easily memorize 5-10 symbols each day. And after you learn hiragana, it will be much easier to start learning how the language works. I don't recommend you to learn japanese based on the western alphabet.
After you learn hiragana you can start learning some conversation. And while nothing substitutes real classes (with a japanese teacher), Teach yourself Japanese is a nice place to start understanding the language. Another place to look for is the Wikibooks, but its still a lot incomplete.