# Conditional probability distribution estimation from numerical data

I am trying to come up with a conditional probability distribution $P(B|A)$, over the continuous variables which look something like this:

A    B
----------
2    5
5    7
8    10
10   15
12   25
..........


etc.

How do I go about finding what distribution will fit my case?

From what I understand, it is a 2-step process. First is that I try to find what would be a good distribution to use to model this and then estimate the parameters assuming that distribution which can then be used in my calculations.