Here are some resources and advice for first year students.
There are a lot of amazing video lectures available online specially for computer science students. Take advantage of these resources.
Participate in programming contests. They will greatly improve your coding skills. And they are a lot of fun.
Google Code Jam
Facebook Hacker Cup
Make it a habit to learn a couple of new words every day. By the time you are in the final year, you would already be prepared for exams like GRE etc.
Asking for help
When you are looking for advice, ask your seniors in the fourth year and not those in the second year. Fourth year students have a lot more experience with what works and what does not.
Make a lot of friends. With batch mates, with seniors, with juniors, with faculty, with staff, with everyone. IITs attract people from all over India. Some of them may come from a culture which is vastly different from yours. Take time to understand them and their culture. Don’t contain yourself to a specific set of people.
Movies, TV Series and Computer Gaming
Don’t spend a lot of time on these things. They create such a high bar of stimulus that nothing can compete with them. Everything else would seem boring compared to them. Don’t waste the four most precious years of your life on movies, tv series and computer gaming.