Downtown Ballard is rich with restaurants, bars, gift shops and even second hand hiking gear. Let meet at the old Tully's, now the Ballard Coffee Works, to map the area.
If this is your first mapping party you don't need to bring anything other than paper and pencil. If you have an iPhone or iPad, Go Map!! is a great mapping app. Android doesn't offer anything nearly as good but you might try Mapzen.
If you want to learn how to use OpenStreetMap new editor, iD, bring you computer with you and we will help.
Have questions, just ask.