Beginners must read Tao Te Ching and South China Ching. Followed by Du, Taiping Jing and Lao Er.

Tao Te Ching and Nanhua Ching are the most basic classics of Taoism. Taoist Collection and Cloud Seven Signs are too complicated to be read at first sight.

If you don't do research, look at the book Common Sense of Taoism published by the Chinese Taoist Association, which should be instructive.