Many on-line training resources are featured in Home Energy Pros On-Line Training Group page.
Other training resources:
Association of Energy Engineers Seminars
Building Performance Association (BPA) Conferences
Building Performance Institute Training & Education
EEBA Houses That Work
EERE National Training and Education Resource
Home Energy Magazine's Training Guide
InterNACHI
RESNET Accredited Training Providers
US Department of Energy Building Technologies Program Webinars
US Department of Energy Training Resources
Weatherization Assistance Program Training Resources