I highly recommend staying in Alfama if you are new to Lisbon and Joana's place is located right in the best part near the Sao Miguel church. Joana is helpful and responsive (thank you!). Her place has been newly remodeled and is very clean, quiet and close to restaurants, mini markets, a lavanderia, and so on. It's pedestrians-only in that ancient and picturesque area. It's only 5-10 minutes walk to the central shopping area and Rossio and 5 minutes to the castle above. The other thing: if you stay in Alfama, you must be prepared for stairs, both outside and inside, and for the cobblestone streets which can be tough on luggage. We used the Metro and the Viva Viagem card to get around. Travel and food are super cheap, but restaurants and bars are tourist prices. For finding a supermarket, I recommend the Pingo Doce Chão do Loureiro, just off Rua da Madalena. For Sintra and Cascais you must use a different ticket from the ticket for Metro. Wonderful city; wonderful place to stay.