vocabulary
 

Does anyone know of the good way to increase my vocabulary?

I would suggest using Anki to drill vocabulary. It's a flash card program that you can get on your computer, iPhone, iPod, etc. The idea behind it is that when you do the flash card you say how well you thought you did (Wrong, Good, Very Good) etc. and based on that the card will not reappear in your deck for a set amount of time. It should appear just often enough for you to remember the word, and the more consistently you believe you're getting the vocab term right, the greater intervals will be in between its appearance. If you get it wrong, however, the intervals restart.

That being introduced, there are a variety of premade decks that you'll be able to find both online and through Anki itself. If I had to suggest a group to start with, I'd look up the 'Japanese Core 2000' deck of cards. It comes in multiple steps (groups of about 100 cards) and you can set how many cards you want to learn per day. The nice thing about it is that in addition to the cards already being made, they have recordings of native speakers saying the words for you, giving you a chance to practice intonation.

I have no idea what your Japanese level is at either, but at some point it might be worth it to try using Japanese -> Japanese Dictionaries when looking up words. At the moment, I use Yahoo's Japanese Online Dictionary, Space Alc and Sanseido's Online Dictionary.

Yahoo is my Japanese -> Japanese dictionary (though it also has a J-E and E-J dictionary), Space ALC I like to use for finding phrases along with words, and Sanseido is good because for a number of words it has an intonation guide (I actually don't remember what each number represents, but if I can find it, I'll let you know. It can tell you whether certain shorter words are High-Low, Low-High and so forth with intonation).

Also not a bad idea, trying to find some native material, reading a few sentences, and picking out some words you don't know. Look up those words, try to find other sentences with them, try to learn their meaning.

Anyways, those are my suggestions. You don't have to do all of them, but they're worth thinking about. If you pick one to start with, I would recommend the Anki deck.

Yes, Anki flashcarding like a madman.

Get Kanji in Context and use that with Anki, and you'll have a ridonculous vocabulary soon enough.

Was reading about the Kanji in context books...good reviews, you think they are worth the buy then?

It is worth nearly any price. It's the single best book I've used outside of textbooks. It's basically the only book I recommend for kanji nowadays, and the side effect of working your way through the book is that you'll learn thousands of vocabulary at the same time. My Anki file for Kanji in Context has 5500 or so vocabulary terms for about 800 kanji or so.

Is your goal for vocabulary in reading and writing, or speaking and listening?

I'll make sure to put them on my too buy list ^___^ thanks for the info

This is a good point. No amount of flashcarding will make you a superb speaker and listener.

I'm sorry, but could you explain a little bit more what Anki is?
I've downloaded it now, and downloaded some RTK system... Is this it?

No idea what RTK is, but if it's "Remembering the Kanji," throw it away.
Anki is a flashcard program. You have to make flashcards for it. This is what I mentioned Kanji in Context for.
DO NOT try to learn kanji individually. Learn them from within actual words. I tried doing kanji by themselves, but I couldn't keep up a pace of even 20 kanji per week, and I wasn't learning any new words while spending my time doing that.