Synchronizing Outlook 2010 Calendar with Sharepoint 2010 website Calendar
Solution 1:
We have been dealing with SharePoint/Outlook issues for a while. The only native option is to manually drag and drop the appointment from your personal calendar to the SharePoint calendar (assuming you can view the calendar in SharePoint).
Solution 2:
We are working on a third party Outlook add-in for this called ProperSync. The next release will have automated calender syncing.
Solution 3:
Simply create a shared calendar in exchange/outlook. Next in Sharepoint add that exchange/outlook calendar as an overlay to you Sharepoint site calendar:
http://office.microsoft.com/en-us/sharepoint-server-help/use-a-group-calendar-HA101810606.aspx
This is a rather clean solution.