Take a look new InfoPath-related resources that were recently published to MSDN and Office Online:
1) The official "What's new in InfoPath 2007" review - excellent way to get to know new stuff that's coming with Office 2007.
2) A series of video walkthroughs on InfoPath 2007:
3) InfoPath Glossary - InfoPath comes with quite a few special terms; clarify any ambuguities with this tool.
Alex WeinsteinProgram Manager