By creating an account, you agree to our terms of service.
I really recommend Tae Kim's Japanese guide (in English). you can find in the site www.guidetojapanese.org/
I use "A course in modern Japanese" published by Nagoya University and "JBridge" but these are quite advanced since I study Japanese at my university. These books use kanji immediately.
But the grammar explanation of these books are good.
Books are really the best way. Or try looking for a website that can help breaking it down. Conjugation is pretty difficult, but once you get the hang of it you'll be fine! There are only 2 radicals (kuru and suru) so the rules always apply. I have a book called "Oxford Japanese Grammar & Verbs" that's very useful.