Olá,
many pilgrims stay at Porto Wine Hostel, Pensão França or Pensõa Duas Nações. All in the internet. They are around the final stop of the airport bus 601. Timetable: http://www.stcp.pt/fotos/horarios/601/volta/601_volta_aept1.pdf
Only 3 - 4 minutes walk from the final stop to these pensões...