It means like "the time when" As the person before me wrote: "図書館で本を借りる とき、カードが要ります。 = When you borrow the book at the library, you need a card (for the library). " You can also use it in past tense with -た　とき (-ta toki) 日本にいたときに、日本語を勉強した。 =When i was in japan, i studied Japanese. I hope it was enough explanation :)

わたし　の　おなか　が　いたい。watashi no onaka ga itai. You can skip the "watashi no" and just say "Onaka ga itai" Onaka(お腹) means stomach, or abdomen. And itai(痛い) means hurts. :)

Remembering the Kanji by James Heisig is a very popular book, and the best if your goal is to be fluent in japanese. It is a very unorthodox method, and if you want to be able to use what you learned right away, i wouldn't recommend this book. However, I learned with this book, and it has made reading and writing kanji my strongest part in the japanese language (i'm jlpt N2 level). But it only gives you benefits if you work with it for a long time.

You don't need to be able to read the japanese characters to be able to understand spoken Japanese. But if you understand written japanese without knowing the Hiragana and Katakana, i'm really surprised! xD Even if it's just for speaking, learning at least one of these will help you alot with recognizing the sounds and with pronounciation. If you want just need to be able to read to get by, and not want to learn more than a little japanese, you might want to start with Katakana, since all loan words are written in katakana. So with a little imagination, at least you can understand the "engrish" in japanese ^^ If you are aiming higher however, learn the Hiragana first, it's the most important one :)

In this case, you could say, 私の友達が来れないと言った。(わたし の ともだち が これない と いった) In English it would be, "my friend said that he can't come". When you want to quote what someone else said you can always say -と　言った or　-って　言った (very informal). and you always add it after whatever the person said. 言う has a lot of other usage as well, for example when you want to say "it's called". Ex: "I'm called David" "ダヴィドと言います" It's a very useful word　^_^ I hope this was helpful!

There is no easy way to learn a language. But the best way to learn any language is to talk and use it as much as possible. So for starters, you should check online for beginner japanese, learn some useful japanese phrases, and as soon as possible, find someone to talk japanese with.

The かなあ shows that it's something you long for. As you probably know, the particle　か shows that it's a question. People often say　-かな add some feeling into the question. and the long あ in -かなあ, indicates that you wish for it, of ask for it. I think you could also translate the sentence as: "Can't it become Friday soon?" with a kind of wishful tone. This is a very difficult thing to explain, and I think it might be easier to learn by doing in this case. Also, i'm not a native speaker.. but i hope my explanation helps anyway! :D