The Artindia pages are a good resource for Indian classical music, with content pertaining to both
Hindustani(northern) and Carnatic(southern) music, as well as classical dance styles from all regions.
Their best feature is the database of links to artists' webpages.
Chandrakantha & David Courtney's Homepage
This site is packed with interesting reading. A must visit if you want background information on classical music.
They have a great section on the history of classical music.
This is an e-zine, which includes lessons on classical music.