You will be on the sell side if you go into investment banking. In a nutshell, you will be working for a brokerage firm that help their customers raise funds in the capital markets or advise them on mergers and acquisitions. You can check out IBankingOasis.com for more information on that. It pays well if you get to the MD level but as an Associate, you will still be pay pretty well compared to other corporate jobs. But the job requires long hours. All I can say is that it is very competitive to get into that industry.

Banking requires long hours and your work schedule will be unpredictable, as an analyst (undergrad level) you can expect to work 80-110 hours a week if you work for a major WallStreet Bank, as an Associate (Graduate level) you can expect to work 80-100 hours a week. Life gets progressively better when you get promoted to VP and above. Exit options are pretty good, bankers often transition into private equity, hedge funds, consulting, corporate development in a fortune 500 corporation (where they get on the CFO career track), investment management/ equity research. Best ways to get in are either from a top tier undergrad or MBA program, alternatively, people with valuation, accounting or consulting backgrounds would have a good shot too.