Problem is:
Japanese consists of THREE entirely different sets of "letters".
In any text those 3 forms of writing are totally freely mixed, depending of the history of a word.
There are Kanji, which are the really weird picture symbols originating from China, where every word has an own complicated symbol.
Used for historic Japanese/Chinese word combinations
And Hiragana, this is a syllabic writing where you have a symbolfor every syllable. Example "Katana" (Sword) is written in 3 symbols Ka-Ta-Na. This is a very easy system to learn as it only consists of about 50 symbols and you can write anything in it.
Used for all day normal stuff like "i go to ..."
And Katakana.
This is analoge and very similar to Hiragana. Historically it is the "male" wirting form, where Hiragana was the female form.
The symbols look somewhat stronger. They are mostly used for "foreign" words.
And of course Japanese people also learn OUR writing, which they call Romanji (roman/latin writing).
Easiest to learn are Hiragana/Katakana and you usually start with Hiragana. Theoretically you can write ANYTHING in Hiragana and Japanese will be able to read it, but some words just have to be written in the other writing for it to be "right" else it will look to them "misspelled".
A good site to start is:
http://www.thejapanesepage.comLearn Hiragana:
http://www.thejapanesepage.com/hiragana.htmKanji Dictionary
http://www.thejapanesepage.com/kanji/kanji/dictionary.htmYou will be required to install Japanese fonts for the page to work and display nice symbolds instead of #######ç%&%ç&**