network analysis and synthesis by kuo ebook
You need a book on network analysis to fully understand poles and zeros. There are a few books here on the subject, just search for them.
I'll try to briefly explain them to you. In the time the domain, the poles of a transfer function H(s) determine the form of the response, i.e. exponential, sinusoidal, ramp, etc. (read up on Laplace transforms for more on this).
In the frequency domain, poles are often used to estimate the bandwidth of a circuit (dominant pole approximation). In general poles and zeros determine the frequency and phase response of a circuit (look up Bode plots for more on this).
Hope this helps, but remember, many books and alotta math are essential if you really want to understand this topic.