When choosing your photographer there are many different aspects to consider, but here is a list of the top things you may want to keep in mind while researching.
Personality - As I mentioned above, your photographer will really be spending a lot of time with you the day of your wedding. Be sure that you feel comfortable with him or her and that your personalities mesh well. You want to meet your photographer in person before you book, or at the least talk to him or her on the phone to get a sense of who they are and start to build a relationship right off the bat.
Style - There are many different styles of photography that can be used to capture your wedding day. Photojournalistic, Traditional/Formal, Artistic and more. Be sure to research different types of styles to see what fits your vision, it will definitely make it easier to narrow down your options.
Package - Does their package include one or two photographers? It is great to have 2 on hand to capture every angle of the wedding, especially when you and your fiance are getting ready at 2 different locations. Do you get to have rights to the images and print them on your own? It used to be hard to come by, but now most photographers will give you all of your images on DVD a couple of months after the event so that you can print them on your own.
Cape Cod Knowledge - How well does your photographer know the Cape, your venue, and the great intimate locations for photos? Be sure that when you hire a photographer they are familiar with your venue, or that they make themselves familiar with it before shooting your wedding. They should know ahead of time where your formals will be taken, where they will get that quick sunset shot, etc. The last thing you want is for him or her to be trying to find locations for photos the day of the event while you and your bridal party are itching to get to cocktail hour.