If I could learn Japanese all over again I'd do it with these materials from the beginning:
1. Readthekanji. (For access to JLPT levels N3 and higher) you pay $5 a month, and you see words INSIDE sentences. You get an English translation of the sentence (which you can hide if you want) and write the Japanese pronunciation. After years of learning languages I know that seeing words inside sentences makes you able to recognize them much more easily in real life than when learning single isolated words a la flashcard software.
2. Animelon. You watch anime and pause the screen and click/hover the Japanese subtitles, and a translation will pop up for the word you chose. They ran the subs through an automatic spacing software and never double-checked them so when the spacing's wrong the dictionary can't find the right word. You can also have English subs, katakana-only subs, etc.
3. OCR software (I'm using a certain phone app that works super well). You can take or load a photo of Japanese, say a manga panel or book page, and it'll convert it to text. You can then copy the words and look them up in the dictionary that way.
4. A Dictionary of Beginner/Intermediate/Advanced Japanese. Pick the one according to your level and figure out the meaning of the grammar via their translated example sentences (their definitions aren't always correct/good so it's best to ignore them and learn it solely based on their example sentences).
5. Manga with furigana (so you can look up unknown words easily + do pronunciation practice by reading aloud). You can download a ton of apps to read manga for free on; you can read it for free on the 3DS; you can visit various websites like these:http://matome.manga-free-online.com/?p=116901http://bzland.net/?topic=38734.0
6. A Japanese 3DS and a flashcart with a bunch of Japanese games loaded. Specifically, I've found that Ni No Kuni and some of the Pokemon games are great even if you're at N5. You can also play whatever other games you want of course, I think the original .hack// games are good if you're at N3 and above, SIMS is good if you're at N2.
7. Vlogs. Yes that's right. Simply type in a food name in Japanese into YouTube and watch bloggers go to restaurants and repeat "It's tasty! It's expensive! Do it this way!" a billion times.
8. Word-replacement software to learn kanji meanings. Ex. "I like eating dogs" becomes "私 好 食ing 犬s". This doesn't actually exist in the way I want it, I just made a half-working one using someone's greasemonkey script and have to pay someone to make a real one once I have money.
9. Learning another easy language first that teaches you about grammar. Yes, that's right — I've been learning Japanese literally 3x faster than my classmates (people who know English, Swedish, German, Serbian etc) just because I knew Esperanto beforehand. I've even been learning faster than some of my classmates who've already been living in Japan for over a year (just about the only people I HAVEN'T been learning faster than so far, have been Koreans). I'd recommend learning Esperanto and some kind of pidgin like Chinook Jargon before or alongside learning Japanese. No, it won't slow down your Japanese, it will literally speed up your Japanese learning even if you're learning all three at the same time. There's tons of research on this topic if you don't believe me, but I can also explain exactly why I have this thinking in another post if someone wants.