In 2006, recent Harvard grad Alexa von Tobel was headed for a job at Morgan Stanley. But though she would soon be managing the bank’s investments, she realized she didn’t know the first thing about her own finances. Most financial guides seemed to be written for middle-aged readers with millions in assets, rather than recent college grads. "I was reading every book I could find, but none of them spoke to me," she says. So she came up with the idea for LearnVest, an online personal-finance resource for young women like her, and ended up writing an 80-page business plan.

After two years at Morgan Stanley, von Tobel entered Harvard Business School in 2008. But upon winning a business plan competition held by Astia, a non-profit that supports women entrepreneurs, she took a five-year leave of absence and invested $75,000 of her Wall Street earnings to start LearnVest in November. She quickly enlisted advisors, including Betsy Morgan, the former CEO of the Huffington Post, and Catherine Levene, the former COO of DailyCandy, to help develop the site’s content and technology. In January 2009, she secured $1.1 million in seed funding from executives at Goldman Sachs.

LearnVest’s site launched a year later and has since signed up more than 100,000 members. It offers online budgeting calculators, video chats with certified financial planners on the company’s staff, and free e-mail tutorials on topics such as opening an IRA. The company earns revenue from advertising and by referring its users to companies such as TD Ameritrade. In April, after just four weeks of fundraising, von Tobel closed a $4.5 million investment round led by Accel Partners, which has also invested in Facebook and Etsy. (Incidentally, Facebook CEO Mark Zuckerberg lived in the same dorm as von Tobel at Harvard.)

Von Tobel likens LearnVest to an online version of The Suze Orman Show, but with the goal of reinforcing positive finance habits early on. “Suze Orman helps 45-year-old women get out of debt,” she says. “Why not reach 20-year-olds to keep them from getting into debt?”