What is the career path to a successful career in private equity investment?

First, you need to get into a target school (typically the Ivies, Stanford, MIT, NYU and a few others). I'd imagine others are more knowledgeable on this part of the process.

Once you're in college, you need to excel in quantitative subjects (note: many people think you can only be finance or accounting major, but this isn't true) and try to position yourself for a job in either investment banking or consulting after graduation. Ideally, during your college years, you'd also involve yourself in several clubs and organizations since personality and character are also key factors that employers consider. Try to secure a junior year internship working at one of these firms, or something that is tangentially relevant (e.g., finance department of a healthcare organization that you could parlay into an investment bank's healthcare group after graduation).

At your investment bank or consulting firm, you need to focus on projects in an industry you're interested in. If you're at an investment bank, try to work on as many transactions as possible (preferably acquisitions since this is more relevant to private equity). Working with your firm's private equity clients at a consulting firm is also a great way to get your foot in the door. While investment banks and consulting firms aren't the only way into private equity, I'd estimate over 95% of professional have these backgrounds (probably 70% from banks, 25% from consulting).

After a few years of work experience, private equity headhunters will start approaching you proactively. You need to clearly demonstrate i) intellectual fortitude, 2) passion for investing and 3) personal integrity (among others). Competition is extremely fierce, but there are a lot of private equity firms out there, and one is bound to be the right fit.

(Same answer also posted on the related question about finance careers in general)

My career in finance has been focused on investing in privately owned companies that are not available via the stock market. Hundreds of thousands of companies are privately owned, ranging from local stores and restaurants to major international companies such as Toys ‘R’ Us and Outback Steakhouse. Before giving any company an investment, I need to understand how a business works including a review of customers, employees, the products or services they provide and places they are offered.

Looking back on high school, I found that the combination of math classes and English classes helped me later in college and in my career. These core skills helped me in college and are now an important foundation for my job. While math is required to analyze a business and see how it makes money, the ability to write clearly is extremely important in communicating with dozens of people at the same time. When I look back, though, I found that participating and eventually running extracurricular clubs at school offered the best way for me to see how a company. Working with my fellow students to raise money for field trips or negotiate with administrators for permission to conduct various programs at the school were the best window to see how the working world actually works.