I've never biked to work, but am going to start next week. It's only about 15 miles round trip. I'm using a single speed bike, but it should be fine because I've gone on farther trips.
Besides a change of clothes, what are the essential items that I need to bring with me? Safety is important so besides a helmet, what safety equipment do I need to have/use?
Any tips would also be helpful because I'm pretty new to this.