Buses run every 20 to 30 minutes from 5am to around 11.30pm between the airport and the train station (Sfr2.80, 15 minutes). The trip by taxi (061 691 77 88, 061 271 22 22) costs around Sfr35.
Once you've booked into a hotel, your mobility ticket covers all public transport (including back to the airport). If you're not staying in town, tickets for buses and trams cost Sfr1.80/2.60/8 for up to four stops/the central zone/day pass.
There are several parking garages between the SBB station and the pedestrian zone. Expect to pay at least Sfr1.50 an hour. Small ferries cross the Rhine at various points (Sfr1.20, day passes not valid).
The SBB train station has bike rental (7am-9pm).