Know your area! I was asked pretty relevant questions regarding the professional area I was entering. I know another interviewee fell down because they didn't know their stuff.
Be ready with a few questions - standard interview practice.
And be ready for a curveball - Mine was "what's your favourite song and why".
Answered - Legal Team (Current Employee) - Dorset
Research their building their prowess and what their ethos is re housing
Answered - Sheltered Housing Manager (Former Employee) - Blandford Forum, Dorset
Read up on history and website
Know your job description and person spec..
Answered - Employment & Training Officer (Current Employee) - Oxford, Oxfordshire
Know your Insights as an individual and make sure you understand your recruiting managers, to ensure the right personality match is there.
Answered - Strategic Research Manager (Former Employee) - Newbury, Berkshire