I know that when you finally have said "yes" to the big question, that is when all the work begins. My simple tip for you regarding finding a photographer is to go with someone you like.
Once you have seen the photo portfolios and compared web sites, go with your gut. If you don't mesh with the photographer, then chances are it will be an irritant on the day when nothing else should matter. You want your wedding day to be as seamless as possible. So, talk with the photographer and ask questions.
Are they flexible? Fun? Creative? What ideas do you want to share with them? Are they open or are they just going to do what they want? Will they allow you to have a disk or do they sell prints, etc...
Ask for what you want and see if it is a fit. Be wary of the cheapest photographer. You frequently get what you pay for. These photos are forever and you don't want a third cousin photo student to take them. Have fun, take a deep breath, and go!