To create a new task, drag out the times that you wish to allocate to the task in the mail panel. To delete a task, click on the task and click the 'Delete' button.
To create a new calender, click the + button at the bottom-right of the interface. To select which calendar to use, click on it.
To view tasks a day at a time or a month at a time, click the corresponding buttons on the task bar.