I am wondering if there is a table or some reference that explains the strength of the beta coefficient.
It depends of the phenomenon that you are studying. If you can tell me more about your regression, I could try to interpret it.
By the way, you should do a t-test, to check if your beta is statistically different from zero. You could check this link to understand what I'm talking about: http://en.wikipedia.org/wiki/Student%27s_t-test.
Any book on regression will explain the $\beta$ coefficient.
$\beta$ refers to the standardized coefficient. It is a measure of how much the dependent variable changes when the independent variable changes by 1 standard deviation. (But see comment below about econometrics).
Is it strong? That is context-dependent. If you tell us the context, someone here may be able to answer.