If you want to take a virtual tour of Venice, it is difficult to do better than through the words of Henry James in Portraits of Places (1883) and Italian Hours (1892).
Othello starts in Venice. Merchant of Venice is the play that made the Rialto so well known.
Best-known to Americans for his litigation with James Whistler (Ruskin wrote that Whistler was a hack who couldn't paint; Whistler sued; a London court agreed with Ruskin), Ruskin spent many years documenting Venice. His work on the architecture is found in The Stones of Venice (1853), on history in St. Mark's Rest (1877) and then there is the Guide to the Principal Pictures of the Academy of Venice.
Twain first visited Venice at the age of 32, on his way to Jerusalem in 1867. His impressions became part of Innocents Abroad (1869) and his observations on the Italians were so popular with the subjects that the book was not published in Italy until 1960. Twain returned in 1878 and wrote about his experience in A Tramp Abroad
"We reached Venice at eight in the evening, and entered a hearse belonging to the Grand Hotel d'Europe. At any rate, it was more like a hearse than anything else, though, to speak by the card, it was a gondola. And this was the storied gondola of Venice! -- the fairy boat in which the princely cavaliers of the olden time were wont to cleave the waters of the moonlit canals and look the eloquence of loe into the soft eyes of patrician eauties, while the gay gondolier in silken doublet touched his guitar and sang as only goldoliers can sing! This was the famed gondola and this the gorgeous gondolier! -- the one an inky, rusty old canoe with a sable hearse-body clapped on to the middle of it, and the other a mangy, barefooted gutter-snipe with a portion of his raiment on exhibition which should have been sacred from public scrutiny. Presently, as he turned a corner and shot his hearse into a dismal ditch between two long rows of towering, untenanted buildings, the gay gondolier began to sing, true to the traditions of his race. I stood it a little while. Then I said:
'Now here, Roderigo Gonzales Michael Angelo, I'm a pilgrim, and a I'm a stranger, but I am not going to have my feelings lacerated by any such caterwauling as that. If that goes on, one of us has got to take water."
-- Innocents Abroad
If you've always wondered what it would be like to be a famous gay German author hanging out in Venice and looking for hot adolescent boys, Death in Venice is a must-read.