What is the local currency?
Indian rupees (INR) is the local currency, which can be exchanged in most hotels. However, please keep in mind that cards are widely accepted at most places as well.
Is it customary to tip?
For your guide and driver, it is customary, though not compulsory to tip them around £10 a day, this would normally be given at the end of the adventure and is completely up to you and whether you feel they have earned it.
For restaurants and bars, giving a 10% tip is fairly normal, which may or may not be included in the bill.