Some photographers claim to be certified. Ask for the phone number of the certifying association to check their status. The photographer may also claim to have been trained by another well-known, more expensive photographer, and then offer the same style for less money. Double check these kind of references. You may want to have an engagement, casual, or formal bridal portrait taken.
Some photographers give only verbal prices or estimated costs.
Get all of your needs in writing including the prices of additional prints, albums, travel, time or other services. Some photographers may be very limiting on time, size of albums, number of prints, types or photograph, etc. This also may be an indication of their flexibility to changes on the wedding day. Many photographers hire assistants or subcontract their weddings. The samples you see at the initial meeting may not be the work of the actual photographer who will photograph your wedding.