We had a very friendly welcome by Joana at the apartment and she showed us around and was happy to answer any questions. There was a handy collection of guidebooks, maps, and lists of nearby restaurants and bars. We never used any public transport as every place we wanted to go was in walking distance - but of course, Porto is a fairly small city.
The apartment was very clean. The bathroom was equipped with big and small towels for all of us, and soaps and shampoo were also at hand. In the kitchen Joana even provided fresh fruit, cookies, coffee etc.