There's no easy way to learn Japanese. I hear they are making a cream but...until then you're just going to have to learn it the hard way. I've been studying for 4 years on and off and here are some things I do to help learn vocabulary, practice grammar, and memorize kanji.
Also, if you want to read furigana on websites there are extensions you can download for your browser.
Chrome IPA Furigana Firefox Furigana Insterter Windows Ruby
Or you can type a URL into this website.
Learn Vocabulary
App: Anki Flashcards
Cost: Free for Droid, $15 for iPhone
How: Download this on your phone/computer and then download the shared deck "Genki 1&2 Vocabulary." These flashcards cover the same vocabulary as the Genki textbooks including all of the stuff from the back of the book where you learn kanji. Each vocabulary word has two cards, one with English on the front and one with Japanese on the front. Each time you view a card, it will give you up to four options of when you want to review that one again based on how easy it was for you.
Why: You can practice anywhere, anytime. Has a great search function when you forget a word you know you should know.
App: JED Japanese English Dictionary
Cost: Free for all
How: Download and look up a word. You want to know the word for 'night'? It's yoru and this is the kanji. Also, here are other words related to 'night,' such as 'night and day,' 'nightmare,' and 'later that night.' Click on the word for a break down of the kanji, and sometimes you'll also be given a list of conjugations and/or example sentences.
Why: It's just the best. Period.
App: Genki Level 1 2nd Edition
Cost: Free for all
How: Flashcards and multiple-choice game for the first Genki textbook. Sadly there is no app for the second Genki book.
Why: Good for beginners
App: Obenkyo
Cost: Free
How: Study hiragana, katakana, kanji, vocabulary, and particles and then test yourself on what you've learned. Also, great grammar explanations.
Why: Great for practicing for the JLPT
Practicing Grammar
Get a notebook app on your phone/computer whatever and organize the grammar you know. Put everything about how to use adjectives together, and so on. Refer back to this list when you're doing homework or writing in Japanese so you can make complex sentences. Don't do the bare minimum when doing grammar homework. Don't try to get a perfect score. Use all the grammar you can in every sentence and learn if you are right or wrong and how to combine everything properly.
Memorize Kanji
Get a notebook app on your phone/computer whatever and organize the grammar you know. Put everything about how to use adjectives together, and so on. Refer back to this list when you're doing homework or writing in Japanese so you can make complex sentences. Don't do the bare minimum when doing grammar homework. Don't try to get a perfect score. Use all the grammar you can in every sentence and learn if you are right or wrong and how to combine everything properly.
Memorize Kanji
I've heard it said that you should learn the radicals first and maybe that helps but that's not how I do it. I started learning to write the kanji in the back of the Genki book in classes as well as learning to recognize the kanji in the chapter dialogues. Make a list of the kanji you're supposed to know and write them over and over until you know them and then never write the hiragana again.
