One useful feature is the ability to schedule appointment slots to make yourself available for tutorials. To do this select the time during which you wish to be available for tutorials in your Google calendar. In the window which pops up you will see top left the word Event and next to this Appointment Slots, click on Appointment Slots and you can edit the duration of each appointment slot in the time you have selected, for example 15 minute intervals.
Click edit details, and you will be taken to a more comprehensive editing window. This window will display a link to the appointment page which you can share with students, you can email this to them or paste the link into Minerva. If you click on the link from this window it will appear that the appointments are not available, this is because the appointment page is not available until you have finished editing the details and clicked save.
For more information follow this link.
Note: You may have heard that the appointment slots feature was to be discontinued by Google. This is only the case for a regular Gmail account, Google have confirmed that Appointment Slots will remain available for Google apps for education users.