For many Japanese Learners, it may be difficult to find the right book to learn Japanese. So in here, I would like to introduce Full of the commonly used books here:

A. JLPT Books Family Full (for N4- N5 level)
1. Nihongo Challenge Kanji N4-5 BookPDF
2. Nihongo Challenge Kotoba N4 BookPDF
3. Nihongo Challenge Bunpo to Yomu N4 BookPDF
4. Goukaku Dekiru N4 N5-AudioCD
5. Goukaku Dekiru N4 N5-Book
6. Tanki Master Drill N5 BookAudioCD
7. Mimi kara oboeru bunpou N4 BookPDF&AudioCD
Download full here
Sources: JLPT
Fan Page:

B. JLPT Books Family Full (for N3 level)
1. Speed Master serial:
2. Soumatome serial:
3. Oboeru serial:
4. Other Serial:
5. Yosou Mondaishu N3
6. JLPT Taisaku Mondai&Yoten Seiri N3 Dokkai
Download full here
Sources: JLPT

C. JLPT Books Family Full (for N2 level)
1. Shin Kanzen Serial:
2. Oboeru Serial:
3. Sou Matome Serial:
4. Other serial:
5. Pattern Betsu Tettei Drill N2
Download full here
Sources: JLPT

D. JLPT Books Family Full (for N1 level)
1. Somatome Serial:
2. Masuta Serial:
3. Other Serial:
Download full here
Sources: JLPT