can you recommend any good katakana/hiragana learning books? i do wanna invest in this language... it's always interested me ^.~; thanks!
You don't really need a book for hiragana/katakana. Use the practice sheets that you can find on this site and elsewhere.
I learnt them by continually writing them out whenever I got the chance. And used them whenever I could instead of romaji
HOWEVER,
I can recommend this book. It's fairly inexpensive and the best of the kana learning books I've come across.
Self Study Kana Workbook.
I like the way the words are being poured into the hinged skull!
Publisher: Jp Trading Inc
ISBN: 4883191583
It comes with a CD so you get the sounds at the same time and pick up some vocabulary and get used to dictation. There are little games and exercises as well.
It also points out common writing mistakes. A teacher will also do this. (It's like learning to write again. I inverted shapes and couldn't read some kana written in different typefaces!)
And then once you've mastered them you turn around and eek! there are thousands of kanji ahead of you. But oddly Japanese is soo much easier to read with a mix of kanji and kana than if it's only kana. hontou ni ganbatte ne!
On kana usage.
Sometimes I think it's just stylistic. Yes the "rule" is katakana for loan words and for emphasis. But I've seen exceptions. The only thing that seems hard and fast is don't mix katakana and hiragana in a single word. Although I'm sure someone can find that exception too. (so I say, it's your name write it how ever you want!) Personally I don't like katakana so much. The shapes are too similar for quick recognition I find. How it makes things stand out for Japanese I'll never know.