NeedtoMeet lets you find the best times for a meeting
The problem of "finding the best time for everyone" is a very common one, and online solutions for scheduling meetings are, accordingly, a dime a dozen.
NeedtoMeet is yet another scheduling solution, but this one actually seems simple enough for non-techies to use. Most other services I have encountered seemed too complex for the uninitiated. They may be good for working with people in a close-knit team who already know the tool but are a bit awkward for first-time users.
NeedtoMeet is somewhat more inviting, at least in my opinion. You get a nicely formatted email with a clear link. You do need to open an account when you use the service for the first time, which is a major drawback, at least to me. Still, once you provide a username and password, you can easily indicate your availability in one of several preselected time slots (chosen by whomever invited you to the meeting). Users can schedule recurring meetings.
If they had Google Calendar integration, it would take things to a whole new level.