Is "Japanese From Zero!" a good book for learning Japanese?
I started learning with the JFZ series, and while the grammar and vocabulary are not bad, I felt like it was too slow to teach writing. Hiragana is taught gradually throughout the first book, and the same is with katakana and the second book. They don't start teaching kanji until the third book. While gradually becoming used to the writing isn't a bad idea, looking back on it I would have much prefered to start learning Kanji ASAP.
I like the Genki textbooks a lot more. It has a whole section for writing lessons (including kanji) and overall, using it is a bit more enjoyable than JFZ.
I would recommend the following:
Genki (Book 1 and Book 2) - Designed by a University Professor from UofM (University of Michigan, which has a great Japanese language program)
Minna no Nihongo (Book 1, 2 and 3) - a little harder because there is no English in the main textbook but a great challenge for reading comprehension.
Japanese for Busy People - teaches the basics using Hiragana, and Romanji if you have issues with learning the Kana. (But I recommend taking the time to master reading and writing both Hiragana and Katakana)
Marugoto Series - From the Japan Foundation, a semi-government body that promotes the Japanese culture and language throughout the world.
Just a few recommendations from me, and the students I tutor.
I mastered the Japanese tree on Duolingo, then after that i bought their second book. It uses hiragana and katakana, on the other hand the Duolingo course uses those two writing systems and Kanji. Other than looking up a few confusing words it was right on my level. Doesn't go too fast, it has writing exercise, and online videos that goes into details. highly recommend it.