There are several things to consider when creating an Appointment in your Outlook calendar. All-day event vs. individual time slot, free vs. busy, setting reminders and recurrence information. You can even insert your e-mail signature in the “Insert” tab.
You can change the time increments shown in your Outlook calendar to allow for smaller more detailed calendar entries. This will work in Outlook 2003, Outlook 2007, and Outlook 2010.