How do I limit the hours people can book on my calendar, or give different calendars different hours?

Availability is set on the staff member, not on the calendar. Open the calendar, go to the Staff tab, select the person and set their schedule. You can set different hours for each day and account for breaks such as lunch. If several people are on one calendar (for example five salespeople on a sales calendar), each person can have different availability.

Because availability is stored per person, if you want different availability on a different calendar, even for the same person, create a separate staff member for that calendar and set its hours there.