Understanding Personas

A persona is a fictitious identity used to represent one of the user groups for who you are designing. They are created by taking both qualitative and quantitative data from; analytics, surveys, interviews user testing and other research techniques that the UX designer uses to craft a sketch of an ideal user.
A good persona needs a name, photo, realistic and research based motivations and goals, and a backstory rooted in reality.

Usability.gov—Personas

http://www.usability.gov/how-to-and-tools/methods/personas.html

Building data based personas

http://www.sitepoint.com/create-data-backed-personas/

How To Create UX Personas (video)

http://uxmastery.com/create-ux-personas/

An Introduction to user personas—UX Lady

http://www.ux-lady.com/introduction-to-user-personas/

UIACCESS.COM—Example Personas

http://www.uiaccess.com/accessucd/personas_eg.html

Free Persona Template

http://fakecrow.com/free-persona-template/