new to changing diapers

Kathryn
Hello!  
I've literally never changed a diaper. Never baby sat, had younger cousins, so what is up with diaper rash cream?  Do you apply it every time or just as needed?  I was reading an article that almost all babies experience some form of diapers rash at one point or another, and my husbands best friends girl friend said their daughter (almost 5 months) has never needed diaper rash cream..  I have no clue!  What's your experience?