Hey,
I am from Bangalore so hopefully I can make this as informative as possible.
Bangalore is situated in the southern part of India, it is the capital city of Karnataka state.
The main language spoken is Kannada, you will however find most people speak atleast some english, so you should not have a lot of problems with the cab driver/waiter/at a store etc.
The weather is usually pleasant, it does not get extremely cold during winter, summer are not over the top hot!
I know a lot of Indians compare Bangalore weather with that of California:)
-First name basis is generally not the norm when the other person is older than you, however, IT companies usually do not follow this rule..you may want to remember this when you maybe meet your friend's parents etc.
-Take off your shoes before you enter someone's home/religious place.
-People wont really expect you to touch their feet:)- it is customary for people to bow down and touch the feet of people older than you as a sign of asking for their blessings.
-Shaking hands is the most formal way of greeting someone, you will embarrass people if you try to kiss them on the cheek as a greeting.
-There are American restaurants in Bangalore-pizza hut, subway, KFC, Mc donalds, TGIF to name a few..you ofcourse will not find any place than will serve beef!Cows are sacred in India!
-Get prepared to experience some horrible traffic:)
-People can get curious sometimes and ask irrelevant questions, if you do not wish to answer, shrug them off gently.
-Get a local to take you out shopping, they know the best places and can get you better deals than if you went alone.
-Try to hire pre paid cabs to go site seeing/shopping to make sure you are not over paying.
-Auto rickshwas are also preferred, pay as much as the meter shows, if it is after 8-9pm, you may be required to pay the fare+50%.(thats the norm)
-There are beautiful places to see in Bangalore and few hundred miles around Bangalore...
-It is relatively safe in Bangalore..however it is always safe to be on guard after dark.
-Most places will not accept credit cards for small amounts, carry a few hundred rupees..
-The biggest American bank in Bangalore is citibank which also has atms around the city.
Please let me know if you have any other specific questions.
Have a wonderful time:)