Delhi airport sucks! If an opportunity is available, the dhoti government officers will rip you off. They won't let you take a whole lot of Indian currency from the airport. Have you seen their currency exchange rate? It is insanely low. You will start to see real India from the Delhi International airport. Once you get out of the airport, you will have hard time finding a taxi. they have prepaid taxis, but they don't work efficiently. The drivers choose passengers. 
At the airport, if you have a greencard, they will take forever to evaluate it. AND DO NOT MAKE YOUR TRANSIT VIA HONGKONG. While returning back to US, the Delhi airport took forever to confirm my tickets. I was the last passenger to catch the plane. You know, I had to run all the way to the f*8king plane. And they offered me nothing. 
If you are going to Nepal and you have a overweight luggage, they will charge you Rs 200 per kg. If it is too heavy, they will take you to a room and ask lots of question. They might take bribe at this point. 

You will start hating India from delhi airport. I'm sure you will see real India. Welcome to DHOTILAND!!!