Prakarana Grantha(teaching manual/introductory treatise):
- Vivekachudamani (Highly recommended), Swami Chinmayananda, Central Chinmaya Mission Trust
- Aparokshanubhuti (Highly recommended), Swami Vimuktananda, Advaita Ashrama
- Drig Drisya Viveka (Recommended), Swami Nikhilananda, Sri Ramakrishna Math
- Atma Bodha, Swami Nikhilananda, Sri Ramakrishna Math
- Vedantasara, Swami Nikhilananda, Sri Ramakrishna Math
Prasthanatrayi(three main scriptures):
- Bhagavad Gita: With the Commentary of Shankaracharya (Highly Recommended), Swami Gambhirananda, Advaita Ashrama
- Upanishads, In particular the Mukya(Main/Principal) Upanishads:
- The Mandukyopanishad: With the Commentary of Gaudapada's Karika And Shankaracharya's Commentary (Very Highly Recommended), Swami Nikhilananda, Sri Ramakrishna Ashrama
- Eight Upanishads: With the Commentary of Shankaracharya (Highly Recommended) (Vol I&II), Swami Gambhirananda, Advaita Ashrama AND/OR The Upanishads (Recommended) (Vol I,II,III&IV), Swami Nikhilananda, Harper & Brothers Publishers New York
- Brahma Sutra Bhasya of Sankaracharya (Recommended) , Swami Gambhirananda, Advaita Ashrama
Auxiliary Texts:
- Ashtavakra Samhita (Very Highly Recommended), Swami Nityaswarupananda, Advaita Ashrama
- Avadhuta Gita of Dattatreya (Highly Recommended), Swami Chetanananda, Advaita Ashrama AND/OR Avadhuta Gita of Dattatreya (Highly Recommended), Swami Ashokananda, Sri Ramakrishna Math
This is by no means all there is to read, however these are some of the texts which are most popular/well regarded. If you are interested, you can find more valuable resources(including youtube links for lectures given by many wonderful teachers) in this website https://www.vedantahub.org/.