To make life at any B-School simple:
1) Start reading business newspapers today (Not just headlines). Try ET, HT Mint, FT, etc. Start now to have some background before you join. (These will start making sense once you start reading more and it won’t happen vice-versa)
2) Start reading editorials, perspectives, analysis from – Economist, Time, HBR [2-5 free articles are available online]
3) If you carry work-ex, revise your Scientific Calculator operations.
4) Build a LinkedIn Profile. Try to detail it as much as possible. [Most B Schools will anyway teach you how to make one but a headstart always helps]
5) Start converting $ to Rs. everytime you read them and vice versa.
6) Start converting millions and billions to lakhs and crores everytime you read them and vice versa.
7) Combine the above two.
8) Adapt to quick reading. You will be expected to read so much, that all your RC Skills from CAT Preps will also feel less.
9) Start loving data. I used to hate data-points memorization. But trust me, you need it.
10) Buy a black covered/jacketed diary. You will join some club, event, etc. You will attend guest speakers. You will attend industry meetings. Maintain a black-covered diary for this purpose alone. Keep a good working pen along with it at all times.
11) Revise your MS Office skills. You will be needing these daily.
12) Get a good email id. Your name, your surname and some number will do. Everything else should be avoided.
13) Become comfortable with Google Apps – Docs, Contacts, Mail, Groups atleast. Gonna be using them a lot.
14) Invest in a smartphone. Or atleast a phone that enables you to check email on the go. Preferably one that pushes in email.
15) Whether a part of dress-code or not, you will need 3-4 pairs of formal-wear. Invest in them.Of-course, a blazer will be required.
List is not exhaustive. You all are requested to add more items as comments and I shall gladly include them in the parent post with credits.