There's a wealth of information there if you know how to "read" it. (Para. 10)
Meaning: You can get a great quantity of information from his action, his clothing and many other things if you know how to understand it.
a wealth of: a large number or quantity of
He has a wealth of experience in this area. 他在这领域有丰富的经验。
n. 量,数量,大量