Ashly Oeltjen
Ashly Oeltjen voted up Cookie Roma's answer

On your employment paperwork you use your legal name.  Then you can tell people at work the name by which you prefer to be addressed. 

Ashly Oeltjen
Ashly Oeltjen voted up Jann Nikka's answer

I always followed Happy's advice.

And as I introduce myself.  First and last name. If its ok people call me _______. Thank you.