I always find that the list of duties is never all covered by the people who interview you, so there is a gap, for instance who does the expenses, do you use travel agents or the internet for bookings, office environment (shared or not), canteen facility, flexible hours or not, pension, health cover, length of probationery period, hours (how long for lunch break, etc), etc... Of course you can always ask more questions on the company itself and not the job, for instance turnover, market share, how long has the company been established, etc.
In my case I have also have some specific questions such as use of French (how much), travel arrangements, use of shorthand, etc
Hope this gives you a few ideas.
Bea
