Question

How do you read IR spectrum graphs?

Answer 1

With difficulty.

Explanation:

See the links in the answer. Infrared spectroscopy is a very indirect method of analysis. If your molecule contains `C=O` or `C-=O` or `N-=O` it may be useful, and it may give you an idea of molecular symmetry. Identification of a molecule by its IR spectrum, even in these days, is untenable.