You have not been very specific so it would be difficult to recommend any equipment. What will your subjects be, landscapes, portraits, sports? Who are your target market, pet owners, weddings, magazines?
There are as many routes into a photography business as there are options for purchasing kit, you might need to narrow things down to get some advice for a certain area of photography.
Nikkor AF-S DX; 18-105 f/3.5-5.6G VR, 55-300 f/4.5-5.6G VR, 35mm f/1.8G
Speedlight SB-700 http://keystrokesukimages.com