You can modify the filters used by Outlook to synch different records. By default, any Appointments you are a participant in (eg required attendee) will get synched, but you could change this.
So an Appointment created in Outlook and tracked to CRM will be synched up to CRM and then the Outlook and CRM records will stay in synch, eg if you change the time of the Appointment in either the other will reflect this.
If you create an Appointment in CRM at which you are an attendee, this will synch to Outlook (for all users who are attendees). These will also stay in synch.
Hope this helps.
Adam Vero, Microsoft Certified Trainer | Microsoft Community Contributor 2011
UK CRM Guru Blog