Take a virtual visit to one of the world's greatest opera houses. The site also has searchable databases about opera. Many pages are in Italian, so get out your translation program.
Find out more about your favorite opera from this Italian site that claims to be "the starting point for the Opera World." The highlight of this site is the "Opera Karaoke" available under the "Opera Sing-along" link. The MIDI files for sing along are basic, but still fun.
Opera Timelines: Italian
Students of opera, you'll find this a handy timeline. Review the dates, composers, and operas organized around Italian opera.
Romantic Era Italian Opera
Visit this online PowerPoint presentation about Italian opera from 1800-1850 by Dr. Steven Kreinberg, Associate Professor of Music History at Temple University. You don't get the professor, but his presentation slides do offer excellent information.