The majority of India works on 220 volts AC 50 Hz. However, it is possible that certain areas have DC supplies and it may be a good idea to check before using electical appliances. Socket sizes vary, so it is well to take along a set of plug adaptors.
Power supply for your electronic devices
You will probably need to get an adapter for your devices. It's pretty easy to get "all-in-one" adapters that you can use to plug your device's power chord into before plugging into the power supply.
It is usual to tip waiters, porters, guides and drivers. An approximate guideline would be as follows:
Restaurants - 10 % of the bill
Porters - Rs.10/- per piece of luggage
Drivers/Guides - Rs.200 per day