A fantastic research project through the Isabella Stewart Gardner Museum is looking in detail at teaching through art discussion. Great resources on the site, including all the research and lots of lesson plans.

Additional Programmes:

Learning Through Art at the Guggenheim Museum

Artful Citizenship at The Wolfsonian

Also both important and interesting is Visual Thinking Strategies which aims to bring a wider understanding and practice of visual literacy into schools.

There are also lots of great art sites in the UK

Young Tate

Tate Tracks

And Creative Partnerships and The Making do some wonderful art projects in schools.