The organizers have booked number of rooms in the nearby Churchill College. Please contact ????? if you are interested in taking this accommodation. Number of rooms is limited.
Alternatively, check out one of the following websites, which provide an extensive list of hotels and B&B in the Cambridge area:
The workshop is taking place at the Institute of Astronomy on Madingley Road, so the closest options are Canterbury House (B&B), Benson House (Guest House), the Premier Inn (Hotel) or the Cambridge Lodge Hotel (Hotel).
The closest and more convenient airport to get to Cambridge is London-Stansted (about 45m by bus or 30m by train). Also not too far (approximately 1h 30m by bus) is London-Luton airport. Several low-cost air companies fly to London-Stansted or London-Luton airports. Among others check RyanAir, EasyJet and GermanWings.
From both airports NationalExpress provides a reasonably good bus service (busses every 45m - 1h from Stansted and every 2h from Luton, depending on the time of the day). Time schedule and prices are on-line. It may be better to book your bus ticket as soon as you know your flight details.
A train service is also provided from Stansted Airport to Cambridge. Schedules and prices can be found at http://www.thetrainline.com.
Eurostar offers quite good fares when buying tickets in advance. So if you are coming from Paris or Bruxells (for more destinations please check the website) consider this option as well. Eurostar trains arrive at St. Pancras International, you will need to get to Kings Cross Station (the two stations are within a few hundred meters) to get the train to Cambridge. For time schedules and prices check this website http://www.thetrainline.com.
Both the Cambridge train and bus stations are quite close to the centre of the city. Local busses schedules can be seen on-line at this website http://www.cambridgeshire.gov.uk/transport/bus_timetables.
Getting to the Institute of Astronomy
The following link takes you to the official map prepared by the University of Cambridge (the map is currently set to show in the centre the location of the Institute of Astronomy but scrolling and zooming are both possible) : link to the map.
The University of Cambridge also has a webpage providing some local information for visitors. This can be found at this link.