Qualifications
There are basically two ways to become a real estate developer. The first is to study the real estate business, work hard as an agent, win accolades, and basically look like a golden child to potential employers. The second route involves already being rich. Then, you'll have the capital to start your own thing. Either way, you'll need a couple of things up front: gumption and knowledge.
Aside from those two things, a college degree is the first thing you'll need to break into the real estate market. A bachelor's degree is good, but a master's in real estate, real estate development, business with a specialty in real estate, law, or finance is even better (source). It also can't hurt to have built up some connections in the biz in order to learn from the best and better position yourself for an opportunity.
Lastly, you'll need those all-important social skills, not only for communicating with other business people but for understanding what folks want to have built in their communities. Mastering those qualities will help you to envision the potential of properties everywhere.