When should I stop taking the pill if I want to get pregnant

The pill should be stopped at least 2-3 months before deciding to get pregnant, so that the chances of fetal malformations are reduced.  During this time, other forms of contraception, like condoms or creams, should be used.  It is important to note that women who have had irregular cycles before starting the pill will have a significant delay  (six months or more) in getting their first period
 

Is it true that the birth control pill causes infertility

Contrary to popular belief, the pill does not cause infertility, nor does it reduce the sex drive.  There is also no benefit to going off the pill for a while (rest period) and then restarting it either.