To find real places in Venice it's not really easy. My suggestion is the Trattoria da Romano in Burano. It is a famous place, so it's recommended to reserve in advance, but it's quite off the beaten path and away from the maddening crowds of Venezia.
Burano is a charming island, famous for lace production.
The house speciality is the risotto: actually you can have it black (with squid ink) and white (with a Venice lagoon fish, called Goh). It's not cheap but it's a very good quality for what you pay.