Poznan is a quite place and many of the
Poznan hotels are located in the city centre. You can find a good hotel no matter if you are a business traveler or a tourist. The Old Town area and the Fair Grounds are very popular for accommodation. You said you need a place in quiet area, so better choose near the Lake Malta that will give you a quiet environment. It's no far from the downtown area and it can be reached by taxi within 5-10 minutes. The Domina Poznan Residence hotel, Rzymski and Ikar hotel are some of the hotels which are located close to the tram or bus stops. I think Willa Arkadia is a best option for you, because it's located in a quiet & peaceful place. It offers you a charming country style accommodation with all.
Poznan offers variety of sightseeing including Mickiewicz Square, Franciscan Church, the Zamek, Renaissance Hall and the National Museum. The Ponzan public
transportation system in well organized, so you can choose a bus or tram to get around. I have been to Poznan last May and the train journey from Poznan to
Warsaw was very comfortable, you can also visit Warsaw as well. Poznan, the most beautiful city of
Poland has many
things to do & see, so visit it & explore it:)