Note that you will need to become a qualified "MEG researcher", as defined in the StandardOperatingProcedures (SOPS) which you need to read before running any studies in the MEG lab.
MEG projects should first be discussed in your scientific group, and then presented at an IIG ImagersInterestGroup for feedback about methodological issues. This is a requirement for CBU projects, though not necessarily for externally-funded projects. Then time "slots" should be requested via the MEG form available here RequestForMegSlots , these should be downloaded, completed and emailed to email@example.com to be considered at the next meeting of the IMC ImagingManagementCommittee. The meetings are every month on a Wednesday and you must send the slot request before the Tuesday morning.
All necessary MEG documents can be found here http://intranet.mrc-cbu.cam.ac.uk/imaging/meg/
Note that MEG projects on healthy volunteers do not require LREC approval, but do require CPREC approval (an existing CPREC for behavioural studies is not sufficient; you will need to make a new CPREC request, or seek an amendment to an existing CPREC approval, to extend it to MEG). A new CPREC application needs to include the usual information about your psychological paradigm/s in addition to explaining that you will be performing the study with MEG. An application also needs to include the information sheet that will be given to participants, for which the following can be used as a template: GeneralVolunteerSheet.