I think KATAKANA.
Because KATAKANA is diffirent from HIRAGANA about expresion.
So you can replace KATAKANA to HIRAGANA.
I recomend NHK text book, which is "Trad Japan."
I don't know GENKI Japan.

Hello, I recommend you to study Katakana before Kanji. There are soooo many Kanji in Japanese, but Katakana has only about 50 characters. Even Japanese people take a lot of time to study Kanji at school... Kanji is a little difficult for us, too. Now, you know Hiragana! Great! Then, studying Katakana won't be so difficult :D

Hummm, I wonder what kind of book is good for you. I will tell you if I find a suitable one for you ;)

I'm afraid I don't know GENKI Japan. Does it seem interesting for you? If so, I want to read it!

ひらがな覚えて、カタカナ覚えて、発音覚える。参考に。

> After I have learned Hiragana what should I concentrate on next ? Katakana or Kanji ?

I recommend Katakana rather than Kanji. Because books for children is often written by only Hiragana and Katakana. Katakana will be more easy to learning than Kanji. Because Katakana characters are one to one correspondence to Hiragana characters. Most Japanese children also learn Hiragana and Katakana first.

>Children's books are probably a great way to learn the language too. Please recommend good books for me!

This site may be useful.
http://ehonnuts.exblog.jp/

I like picture books by Mitsumasa Anno ( 安野光雅 "Anno, Mitsumasa" ), too.
http://en.wikipedia.org/wiki/Mitsumasa_Anno
His books are beautiful and interesting.

I like picture books by Taro Gomi ( 五味太郎 "Gomi, Taro" ), too.
http://en.wikipedia.org/wiki/Tar%C5%8D_Gomi
His books are colorful and comical.

Books by Anno and Gomi are very good for not only children but also adults.

Try Google Images search. "安野光雅" and "五味太郎" :)

Wow! You are all so helpful, thank you all very much !

I haven't read Genki 1 yet, but I will let you know if it's valuable reading or not. I will definately learn Katakana after my Hiragana is set..Thank you.It will still take some time before my Hiragana is learned ;). I'm concentrating on the basic 46 syllables for now..and then Dakuon, Handakuon and Yoon.

Because your signs are so different from roman letters it really helps to connect the signs to something they remind me of. Here are some of them:

tsu = tsunami ( it looks like a wave )

shi = fishing hook

etc...:)

Once again, thank you for helping me, and please do not hesitate to contact me if you're interested in learning Norwegian ;)

Hi, Sequax.

　　つ tsu = tsunami ( it looks like a wave )
　　し shi = fishing hook

They are wonderful!

Please tell me more! :D

Hi, Kimura :)

Se = picket fence

So = the sail of a sailboat

Su = a " t " with a loop

:)

There are some dictionaries for you. You will find them at book store. I have seen some of them. English-->eigo (英語 English) and nihongo-->English. I mean this: You look for "dog", dog inu 犬. Do you get it? I do not know exactly the name of the dictionary, but it is published from Collins Dictionary. Please ask clerk of the shop.

Thank you very much, Sequax! :D

Hmm... Interesting. :)

I like former "つ" and "し".
They seems much nicer because they have sound identities in their names of pictorial images.

So I searched books about similar idea in Google Book Search.
I found some books. ( But not the same mnemonic pictures... :( )

"Hiragana/Katakana in 48 minutes: teacher guide" By Hiroko Kakkenbusshu, Yvonne Broekman Vincent

"Kana Can be Easy" By Kunihiko Ogawa

The "48 minutes" book can be viewed on Google Book Search.
It is wonderful for me.

How did I memorize Hiragana and Katakana characters in my childhood...?

Thank you for your kindness. :)

It's necessary to memorize Katakana if you continues to learn Japanese. So, learn Katakana first. After you learn Hiragana and Katakana, you can start to learn Kanji. We use soooooo many Kanji!!

げんき is a good text book. It has a website and useful learning pages.
がんばってね。

http://genki.japantimes.co.jp/self/self.en.html