Sector-Specific Trainings and Certifications are often listed through the websites of national sector-specific organizations.
Check out Greener Skills, a great report on the different types of credentials and certifications that will be useful as you develop your skills for a green-collar career.
The Interstate Renewable Energy Council website has a map of training resources, listed by region. It is only a listing – similar to the Yellow Pages. It does not imply approval of the courses or providers listed, so read the information on the page telling you how to check these programs for quality: www.irecusa.org/trainingCatalog
The North American Board of Certified Energy Practitioners website has information about solar energy trainings: http://www.nabcep.org/resources/training
This website lists energy-rater training providers accredited by the Residential Energy Services Network: http://www.natresnet.org/programs/training/directory.aspx
This document lists all the training providers that Building Performance Institute has recognized for their certification exams: http://www.bpi.org/documents/BPI_Recognized_Primary_Training_Providers.pdf
When choosing a training program, it is important to find one that is connected to employment opportunities and is not too expensive. The most important thing is getting steady work once you complete your program.