We know a fair bit. There were some houses preserved in Rome itself, but there are also the cities of Pompeii and Herculaneum, which were buried by Vesuvius in 79 AD. So we've got these two towns, beautifully preserved, that weren't major centres, but were just prosperous towns.

In terms of sources, to take a closer look at what the city actually looks like now, this has some pretty good pictures.

I'm sorry I can't provide more scholarly sources, but most of the images I have in mind have been shown to me in passing during lectures!