Delhi is the capital of the largest democracy in the world. With a population of 16 million (and growing), Delhi can be overwhelming to a first time visitor. Therefore, my advice is to go gentle on your first day so that you can take in the essence of Delhi – its sound (which will be loud to the point of ear drum bursting), smell and visuals.
Delhi is a very spread out city with chaotic traffic, so you have to plan your Delhi trip in such a way that you cover a lot in the limited time that you have. I normally divide it into South Delhi, central Delhi and Old Delhi. You cannot easily plan your Delhi trip hour-by-hour because getting from one place to the next can take you an hour or maybe more, depending on the traffic, any VIP movement, festival or religious processions.
Here’s a proposed itinerary to help you out.