Just passing on info....there was a good article in Martha Stewart Weddings about tipping. They gave percentages and dollar amounts for each vendor.
Of course, they noted that you should only give tips to vendors AFTER they have gone beyond the call and done a good job.
Finally, they noted which vendors to tip and which vendors are typically not tipped. She noted that the photographer and florist are generally not tipped. In addition, she stated that if the vendor is the owner of the business, he/she should not be tipped.