Create Workflow
http://office.microsoft.com/en-us/sharepoint-designer-help/create-a-workflow-HA010100591.aspx
Office Integration with Sharepoint 2007 and Outlook 2007
http://www.outlookexchange.com/Articles/JasonSherry/sherry_c24p1.asp
Whitepaper on 2003/2007 Integration
http://blogs.technet.com/b/john_westworth/archive/2007/04/21/sharepoint-document-microsoft-office-programs-and-sharepoint-products-and-technologies-integration-fair-good-better-best.aspx