Money - unless you arrive in India before joining the trip there is nowhere to change your money other than at Mumbai airport where the exchange rate is not very good. It would pay you to arrange to change your money back at a bank in Delhi on the last day - keeping enough of course for your last meal out that evening.
Take a sink plug - in all of the accommodation there are signs saying save water, but none of the sinks has plugs, so while washing/shaving, etc the water just goes down the drain.
Sightings - don't be too disappointed if you don't see a tiger. On the 14 game drives the maximum number of sightings overall by our group were four, some only had 2 and it is very hard to keep going out, not seeing any and then coming back at the end of the drive to find that others in your group had wonderful sightings. Of course there is plenty of other wild ife to see including spotted deer, monkeys, peacocks, bird life, etc and by your last game drive you'll say to yourself "and another spotted deer"!
Food - enjoy the indian food because it's better than any you will get at home.