If you need to figure out a date among a group of people, like which day is best for Latin club to meet or when it’s best to have a reading group, http://doodle.com/ is a great way to coordinate it.
This is a free online tool that lets you define a range of dates and then lets other people say whether or not that date works. This means everyone can see that, for example, Thursday evening works for nine out of ten people, more than any other date. Also, if you’re trying to schedule shifts to cover something, people can see which shifts need to be covered.