On the visa application form, I typically put the name, address, and contact person/number of the first place I'm staying.

Whatever city you are starting your travels in, check for a YMCA, they are usually clean and cheap. Book 1 night there and use this address, then, if you change your plans and change hotels, np. (Unless you are staying in a border region, there is no need to Register as a foreigner as in the past) the hotel or ashram will register your stay automatically... I also suggest the 10 year visa, it's a bit more then the 1 year visa, but will allow you to stay for as many 6 month visits as you like, provided you exit the country for a few days, before returning... Thailand and Nepal are wonderful at these times. Enjoy your stay, North India in the summer or South India in the winter, either way have fun...