Read the consultation paper on the new CCTV Code of Practice. Even if this doesn’t apply to your jurisdiction, the downloadable CCTV data protection code of practice consultation draft provides useful advice on selecting and siting cameras, using equipment and best practice for storage of recored materials.
Downloadable from:
http://www.ico.gov.uk/upload/documents/library/data_protection/practical_application/ico_cctv_consultation_draft_final.pdf