The first public opera house, Teatro San Cassiano, opened in Venice in 1637. The most important feature of Venetian opera was the fact that it completely depended on making money from the public. Florentine and Roman operas were paid for by the ruling class.
Musical style traits for opera in seventeenth century Venice were
The bel canto aria was fully established in Didone (1641) by Francesco Cavalli (1602-76), also Giasone (1649), La Calisto (1651) and Ercole Amante (1662).
Early examples of this school were the final operas of Monteverdi: Il Ritorno d'Ulisse in Patria (1641) and La Incoronazione di Poppea (1642). These two operas will appear in modern day productions.
For me a famous modern production of a Venetian style opera is Francesco Cavalli's La Calisto, a work from 1651.
I very much recommend the René Jacobs version of this opera available on the film below. It is available on YouTube in audio only, but you may buy it on Amazon with full staging.
These people are up to no good. I have a very deep feeling that this production will tell you more about Venetian opera than anything I could possibly write, or anything you will read in textbooks. Gods and goddesses come and go on bizarre stage machinery. Many claims of chastity are proclaimed, but none are actually maintained. Giove starts out as a baritone, and then makes a fabulous change over to falsetto in his disguise as Diana. There is wonderful coloratura throughout and a complete utter lack of pomposity.
Here is a different production with more famous singers and rather bad video.
Viva Italia.