Use the Internet for Ofsted reports. Type in the head's name on the Oftsed website and find out his or her track record. And visit the school's and the LEA's websites.
Your interview day will include a school tour, but have a recce beforehand if you can. At least check out the area and your route as well as proximity to nurseries and schools for your own children. If it's summer, you could turn up at the school fete.
There's no substitute for talking to people who have experience of the school. If you live locally, you can almost certainly find a teacher or parent to talk to, but beware out-of-date information and the sound of grinding axes.
Go back to the original ad and to the information provided by the school and ask yourself how the image might translate.
Beware missing information too: does that ad mention contact time or professional development? If not, you need to find out why.
You may want to work in a special measures or serious weaknesses school. Or you may not. Identify them by words such as "innovative", "challenging" and "cutting edge".
The oversubscribed school may be overcrowded, so look out for workspace when you're on that tour. The "exceptionally good value-for-money" school may be a lean and mean place to work.
When you've gathered your impressions, write down a few headings such as size, intake, pastoral, results, community. Then see what you think and what you'd like to know. It's useful to compare with your present job and see whether you think this one will be an improvement. Above all, compare the school you're interested in with the job you want.