Introduction to designing a form in InfoPath 2010
http://office.microsoft.com/en-us/infopath-help/introduction-to-designing-a-form-in-infopath-2010-HA101821252.aspx?CTT=1

InfoPath 2010 features unavailable in Web browser forms
http://office.microsoft.com/en-us/infopath-help/infopath-2010-features-unavailable-in-web-browser-forms-HA101732796.aspx?CTT=1

InfoPath 2010 Technical Articles
http://msdn.microsoft.com/en-us/library/gg271284.aspx

Building SharePoint Applications with InfoPath 2010 (Part 1 of 2)
http://msdn.microsoft.com/en-us/library/ff961896.aspx

Building SharePoint Applications with InfoPath 2010 (Part 2 of 2) (MSDN refresh)
http://msdn.microsoft.com/en-us/library/ff961895.aspx

Step-by-step tutorial
InfoPath 2010 Training Labs
http://msdn.microsoft.com/en-us/library/office/gg180739(v=office.14).aspx

InfoPath 2010 and Forms Services
http://msdn.microsoft.com/en-us/gg621277