Learning Hiragana & Katakana
JapanesePod101 offers a few fantastic video series on learning to read and write the Japanese letters, which are called kana. They're the ones I learned from! These links will take you to their YouTube playlists.10-Day Hiragana Challenge Video Series
10-Day Katakana Challenge Video Series
Kantan Kana Video Series
Using flashcards with Tinycards is a great way to reinforce what you're learning. Plus, using these decks will count toward your Duolingo progress!
Tinycards Flashcard Deck: Hiragana
Tinycards Flashcard Deck: Katakana
Grammar and Vocabulary
Puni Puni Japan is a colorful website filled with fun lessons on all sorts of subjects. One of my favorite parts is the collection of bite-sized grammar lessons! Check out their YouTube channel, too.JapanesePod101.com is one of the best Japanese-learning websites out there. You can create a free lifetime account and dive into their library of audio and video lessons. You can access even more with a paid premium membership, but there are tons and tons of lessons that don't cost anything.
Online Courses
Duolingo is my personal go-to. It's free, it's fun, and it works! You can track your progress, set goals, and connect with other users on the forums. Sometimes you'll need to do a little extra research on the side to completely understand what you're learning, which isn't a bad thing.Although I've only tried the first few lessons, I've heard good things about LingoDeer. It requires a paid subscription; however, you can try out the first few lessons for free.
Dictionaries
Jisho.org is a wonderful dictionary with lots of handy features. It's my go-to. It tends to be rather formal, which is great for learning the proper and most polite forms of words, but sometimes very casual forms of words aren't directly listed.Google Translate isn't actually a dictionary, but I still use it every day. It's especially useful for deciphering informal dialogue in manga. Although Google Translate is a powerful tool, don't rely on it alone. Always cross-reference with a dictionary to be sure what it's telling you is what you want it to say.
The Jaded Network is unique because it's a dictionary of Japanese onomatopoeia— sound effect words! It's especially great for reading manga, because many Japanese-to-English dictionaries don't list sound effects.