Portrait photography is a pretty broad thing^^ Do you mean in a studio, outdoors in bright light, outdoors in low light? Or a mix of everything?
With enough light like in a studio or in bright conditions I'll carefully say that the camera body doesn't matter too much. The D7000 that I recommended would do a great job there, but a full frame body would be even better, but those are vastly more expensive but give you better results on low light. The D7000 costs around $400 to $500 right now if you want one in great condition.
As for lenses, that really depends. "Regular" portraits are usually shot between ~50mm and ~200mm. But you can take portraits with pretty much any lens, it just depends on what you want to do!
If you want to take portraits with great bokeh (blurry backgrounds) you might want to invest in lenses with a big aperture. For example, a decent place to start would be the Nikkor 50mm f/1.8G. 50mm are a neat focal length for portraits on a DX camera and the aperture of f/1.8 let's you blur out the backgrounds quite nicely. You can get it for under 200 bucks.
Once you have more experience you can look into different lenses and lighting equipment.
This is just my recommendation for a starting point. I am not a exactly a portrait photographer, so I'm sure others can give you even better advice^^
I also agree with Designer, just look around for camera prices a little. Get an overview of what things cost right now and then tell us what you want to spend.