Practise your Italian at the Toletta bookshop
This place was one of those shops you stumble over, then wish you could spend the day. Not only did the Toletta have a really good selection of English books - from classics (including Thomas Mann's Death in Venice, natch) and recent novels to a healthy selection of children's titles to keep my companion happy - but the wealth of maps and guides made it feel like a one-stop shop for learning about Venice. Then there were the staff, who happily engaged with us in our broken Italian and helped us with our grammar. It's hard to feel encouraged to speak Italian in Venice, where the locals' English is so good - but this was a good place to start.