Meet your photographer in person.  Larger wedding studios might have up to 25 photographers on staff.   Make sure that their style of photography is what you prefer.  Some studios will select a photographer to send to your wedding themselves.
What is the the personality of the photographer?  Do you and the photographer get along?  Do you think that the photographer will interact with your guests well?  You want to be sure that you and the photographer are a "good fit".
Try to find a reception hall that is within a ½ hour car ride from the church.  Remember, you will be in your bridal gown during the ride to the reception and you don't want the ride to be terribly long.
Many brides prefer outside portraits to help create an individual wedding memory.  Finding a park, fountain or forest preserve between the church and reception hall can help simplify the day.  This is to prevent you from running all over the countryside trying to create magic moments.
Look for a paved path or sidewalk at the outdoor location.  If it has rained recently, the ground might be too soft or muddy for narrow heals.  It will also help keep your dress clean too.
Ask the florist to deliver the flowers about 1/2 hour before the photographer arrives.  Even if the florist arrives 1/2 hour late, the photographer can still take the pre-wedding photos with all of those beautiful flowers.