Hello and welcome. Here are my suggestions.
Probably the easiest board to get started with is the Uno. It seems to be the most popular and is a reasonable cost, especially if you look on eBay or your local electronics markets in India.
As far as getting up the learning curve, I found the easiest was to look for tutorials (see http://arduino.cc/en/Tutorial/Links
as a starting point) and I found the Tronixstuff series really useful. The tutorials will have some components that you will need to buy, so make up a list and get them all at once so you can do a few exercises at a time :-). After that, complex projects are just a matter of combining smaller ones.