If you're like most people, the warmer weather has you jonesing to get outside and run. If you're a beginner, or you're shopping for new shoes, the plethora of available models can be very confusing. For me, the most important decision is to choose how I'm going to use the shoes: road or trail? short or long? speed or distance? The next thing to do is do some research shoe company lasts, the form they use to make their shoes. If you have a broad foot and a narrow heel, there is no use looking at running shoes that can't accommodate you comfortably. REI has a nice basic infographic on choosing running shoes:
Don't stop there, though. Try on as many pairs as you can from the ones you've chosen through your research. Better running stores will let you run in them outside, or on a treadmill at minimum. I've found that, beyond initial stiffness that can be worn in, uncomfortable shoes remain that way. Don't be swayed by the cool design or the fact that your favorite elite runner wears those shoes - if they're not comfy, let them go.