Here are some popular Jain books you might consider:

• Tattvartha Sutra (Umaswati) — A comprehensive, concise summary of Jain philosophy, ethics, and cosmology. Widely taught in both Digambara and Śvetāmbara traditions, though some details differ by sect.
• Uttarādhyāyā (Uttarādhyayana Sutra) — A collection of stories and moral dialogues that illustrate Jain ethics and the path to liberation; valued for practical guidance and contemplative practice.
• Kalpa Śāstra — The biographical and historical account of tirthankaras and key Jain chronicle material; central in Śvetāmbara tradition for festive recitations during Paryushan and festivals.
• Bhāvanā/Pravacana texts (various namokar mantras, bhakti stotra collections) — Helpful for daily devotion, mindfulness, and cultivating right conduct (śīla).

If you want, I can tailor recommendations to your interest (philosophy, stories of the Tirthankaras, daily practice, or scholarly study) and point you to a specific JainKnowledge.com page that covers that book.