Check out this great 11-minute video by the co-author, Laura Rogers, of Using Microsoft 2010 InfoPath with Microsoft SharePoint 2010 Step by Step. It’s based on Chapter 10, “InfoPath Integration with SharePoint Designer Workflows.”
You’ll find the video at:
http://www.youtube.com/watch?v=B9uwR01T1MY
You can buy the book at:
http://shop.oreilly.com/product/0790145330963.do