The Tao Te Ching

One essential piece of reading is The Tao Te Ching. Here is an excerpt;

The Tao that can be told is not the eternal Tao.
The name that can be named is not the eternal name.
The nameless is the beginning of heaven and Earth.
The named is the mother of the ten thousand things.
Ever desireless, one can see the mystery.
Ever desiring, one sees the manifestations.
These two spring from the same source but differ in name; this appears as darkness.
Darkness within darkness.
The gate to all mystery.

One way to read the Tao Te Ching is to visit https://ttc.tasuki.org/display:Year:1972,1988,1996,2004/section:1
Another way to read it is to purchase a copy of one of the translations..I recommend the older ones because they are more literal and contain less paraphrasing.
(This link is an Amazon Affiliate link!)
Tao Te Ching: Text Only Edition