SharePoint 2007 and 2010 allows users with Outlook 2007 or greater to automatically synchronize SharePoint items to the local Outlook instance. The synchronization between SharePoint and Outlook allows users to sync calendar items, contacts and document libraries. You can also synchronize other SharePoint objects like Tasks, Lists, and Surveys, but they will not be covered in this article.
Calendar:
To synchronize a SharePoint Calendar to Outlook, navigate to the Calendar in Internet Explorer and select the “Calendar Tools> Calendar” ribbon bar, then select Connect to Outlook.

After you select Connect to Outlook, you will receive a warning from Internet Explorer about the synchronization request. Select Allow.

After you tell Outlook to allow the Synchronization, you may have to authenticate against the SharePoint server.
After you allow the Synchronization your Calendar items will be downloaded to your Calendar view or under the SharePoint List category in Outlook.

Contacts:
To synchronize SharePoint Contacts to Outlook, navigate to the Contacts in Internet Explorer and select the “List Tools> List” ribbon bar, then select Connect to Outlook.
After you select Connect to Outlook, you will receive a warning from Internet Explorer about the synchronization request. Select Allow.
You will then receive a warning from Outlook about the synchronization request. Select Yes.
After you tell Outlook to allow the Synchronization, you may have to authenticate against the SharePoint server.
After you allow the Synchronization your contacts will be downloaded to your Contacts view or under the SharePoint List category in Outlook.
Document Libraries
To synchronize SharePoint Document Libraries to Outlook, navigate to the library in Internet Explorer and select the “Library Tools> Library” ribbon bar, then select Connect to Outlook.
After you select Connect to Outlook, you will receive a warning from Internet Explorer about the synchronization request. Select Allow.
You will then receive a warning from Outlook about the synchronization request. Select Yes.
After you tell Outlook to allow the Synchronization, you may have to authenticate against the SharePoint server.
After you accept the Outlook Security warning, there will be a new Category of items in your “Folder List” labeled as “SharePoint Lists” – your document library items will be downloaded to the respective folder of the “Document Library” in SharePoint.
