Here's a trap that newbies to regression analysis have been known to fall into. It's to do with comparing the numerical values of the point estimates of regression coefficients, and drawing conclusions that may not actually be justified.
What I have in mind is the following sort of situation. Suppose that Betsy (name changed to protect the innocent) has estimated a regression model that looks like this:
Y = 0.4 + 3.0X1 - 0.7X2 + 6.0X3 +.....+ residual .
Betsy is really proud of her first OLS regression, and tells her friends that "X3 is two times more important in explaining y than is X1" (or words to that effect).
Putting to one side such issues as statistical significance (I haven't reported any standard errors for the estimated coefficients), Is Betsy entitled to make such a statement - based on the earth-shattering observation that "six equals three times two"?