To come to CERN: http://home.web.cern.ch/directions
Useful information about your arrival to CERN:
At your arrival, you will have to pick up your visitor card. If you arrive between 8.00 am and 5.45 pm, you can collect your card at the Reception (building 33). If you arrive after 5.45 pm, please go directly to Entrance B.
If you stay at CERN Hotel, you will need to present your with an ID card/Passport at the Hostel Reception.
More info : http://gs-dep.web.cern.ch/en/CERN_Housing