I myself am trying to learn Japanese....
And i foudn these two books which are AMAZING.
Their ISBN(S) are
0-07-142119-X
Which is called Instant Japanese.
With this you basically learn the Basics FAST. You should be speaking enough japanese to survive a couple weeks in japan (If you were to go) and it takes about 6 weeks.
The next book i give 5/5 stars!!
The ISBN is
0-07-141985-3
This one is called Beginner's Japanese script.
It teaches you basic Kanji. How to Read/Write Kanji.
How to read and write Hiragana and Katakana.
Your Numbers 1-1,00,000.

These are Really Helpful books. And AMAZING for Beginners,