How do I calculate the variance of the ratio of two independent variables?

#1
If I have two independent variables (say X and Y) with their respective variances (or standard deviation), how could I calculate the mean and variance of the resultant division of variable X from variable Y?
I have come across some "first order Taylor series", but as a non mathematician it is fairly hard to me to follow up the explanations. Could someone recommend any literature? Thanks in advance