My guide to learning Japanese through self study
These are just my suggestions for tools and strategies to learning Japanese on your own based on my own experiences. I'm going by JLPT levels to easily break up the language into 5 experience levels. JLPT stands for "Japanese Learning Proficiency Test." It's the standard test for judging one's proficiency in japanese. Even if you're not interested in taking the test itself, you can use it to help find materials at your level.
The first thing you want to do is learn Hiragana and Katakana. I used Real Kana, but it should only take a few weeks so you can't go wrong choosing your study method.
At this point you don't want to spend a lot of time on grammar, so just read the first section or two of Tae Kim's Guide to Japanese to get a nice basic intro to Japanese
Your main focus should be to build up your vocabulary. I wrote the app JLPT SRS using my favorite SRS style.
Time to read the rest of Tae Kim's Guide to Japanese to get some basic grammar
You're still going to have plenty of missing vocabulary, so start in on N4 words in your favorite SRS. You can continue to use my app JLPT SRS to grind those words.
You might be able avoid listening practice at N5 if you're an Otaku, but at N4 you'll need some. My app Ki-Kikoeru has short easy to follow Japanese audio samples from tatoeba.org
You're still in need some vocabulary, but you'll notice basic SRS is not as an effective study tool as it once was. But JLPT SRS has some settings you can tinker with to help keep it at your level.
Now it's time for reading practice! My app Reibun can help you get started with practice sentences including english definitions. Also, Yotsuba is a great manga to start with.
Keep up with that listening practice! Ki-Kikoeru can still help, and NHK News Easier has a lot of short readings of news stories.
You can still finish out your SRS - but reading is going to be much more crucial at this level. NHK News Easier can be very helpful at this point. It pulls in articles from NHK Easy News and matches up words to their english definitions.
Aside from the sources I've already mentioned if you have Netflix, some of it's originals will come with Japanese audio and subtitles. The chrome extension Language Learning with Netflix is a great since it'll allow you to slow down the audio and have both english and japanese subtitles.
Just keep reading away :) Good luck!
At this level you should be able to understand a bit more that's going on in normal TV programs. So binge away with Language Learning with Netflix :)