How to use a potentiometer

I want to connect a potentiometer to my leo bodnar - but how is it done? I can see it has 3 pins - and on the the leo there is a +5v,gnd and number. Should i use the +5v too? or only the gnd and number? and how can i know which pin is what on the potentiometer?

Have a look here: http://www.leobodnar.com/products/BU0836/ there are diagrams and the lot!