The customer my not always be right... but your coworkers can always be wrong!
There are certain respects given to event specialists who have been in the business a bit longer than others- going on a decade of extravaganza planning, I, as well as my fellow planners, expect the newbies to act accordingly.
This being said, there is no reason to step on toes, when you can delicately glide over your coworkers feet without leaving an impression upon them.
Please, follow guidelines laid out by years of corporate expertise in your handbook, and read between the lines. Remember to always observe your fellow workers and how they treat each space in the office. Is certain software only available for use on one or two computers- give up the one someone needs for space planning while you email somewhere else. Is there a fitting room shortage- ask the bridal party if they can share rooms, or if they mind taking turns. Is there a pictorial wedding book that multiple brides need to see- try to pull the images up from the internet or make color copies to look at while you wait for the real deal.
Expressing concern and respect for your coworkers time and energy will help you climb the ladder of success, rather than knocking yourself down a rung or two when you upset someone who has some form of seniority.
With all the bridezillas in the world, we don't want to go creating EventPlannerZilla, too... right?