Always do your research - check their work, read the reviews and spend time talking to them first. You should aim to partner with a photographer who you'll see as a friend on your wedding day, not just another vendor. If you can do that, I promise that your experience will be infinitely better. You will have more fun, be relaxed in front of camera (even when you're not aware of it), you'll be less likely to second guess your photographer's decisions, you'll trust them and encourage them to take risks and you'll be more inclined to reveal the real you. Remember, this is all about you guys, your story, your people, your moments.
Don't take any risks. Take time with the decision and don't be driven by cost alone. I've seen too many horror stories in the last 10 years to know that skimping on wedding photography rarely works out. It's true what they say, this really is one of the most important investments you're likely to make.