making NAT ip on mikrotik rb750g

hello… I am new on mikrotik, could somebody tech me how to configure the mikrotik regarding making NAT
thank you for your time

The following guide covers basic configuration: http://wiki.mikrotik.com/wiki/Manual:Initial_Configuration

thank you for the information, actually i want natting from ISP to my core switch…
but to get connection to internet must enter static ip until alternate dns server (already got from my ISP)
Sorry for bad english …