Review Their Work
You may have heard it before, and there is truth to this piece of advice, ask to see a full wedding album.
Your decision to hire your wedding photographer should not be based upon a couple photographs that you fell in love with. Photographers will always put their best foot forward and with good reason. However, you don't want to hire a wedding photographer based on a select few shots, you want a wedding photographer that is well-rounded. And a full wedding album will give you that perspective.
It will also help to see photographs from weddings at similar locations to your wedding venue. This will give you better insight as to the wedding photographers abilities in specific conditions. If you are having an outdoor wedding, take a look at photographs where the photographer utilized natural lighting. If you are saying "I do" in a large chapel, take a look at some indoor wedding shots, maybe some with up-lighting. This will help you to see how your wedding photographer will be able to work with you and your unique wedding.
Compare Their Services
Many photographers will offer set packages for you to choose from. This may be helpful if you have no idea what you might want from your wedding photographer. If you do know what you want, and may be very specific in your needs for your wedding photography, it may be beneficial to find a wedding photographer who will be able to cater to your needs.
Generally, wedding photography works on a standard of coverage hours. You will want to ensure that your photographer is available for your wedding during the times that you want them. Most weddings are covered from the getting ready stages, through the ceremony and even into the reception. Ask questions about what your wedding photographer offers as this will help you decide on what you want for your wedding.
You may even want to consider additional photoshoots before your actual wedding date. Engagement shoots are very popular for multiple reasons. Aside from the obvious reason of having photos of yourself while being engaged, it offers a great opportunity to get used to your photographer. Most people are camera-shy. It is a natural tendency when asked to pose in front of a camera. An engagement shoot allows you to get used to posing with your partner in front of a camera. Think of it as a practice run - because when the big day comes, there are no re-shoots. You will want to be sure you are comfortable with a photographer and vice versa.