If you are going to talk about using tax return money to buy camera gear, it would be helpful to know an estimate of how much you expect to get back...or what your budget is.
I would not want to try to direct you on which specific gear to get, unless I know more about your preferences, of how you like to shoot, or how ambitious you are willing to be.
Do you like a set of reasonably fast prime lenses, or do you prefer to keep from changing lenses often, by using a zoom?
Since you have a Nikon camera, you could get fast prime lenses super cheap, if you are willing to use old, manual focus lenses. You will also, of course, have to set your aperture manually too, but the glass you can get for the price, might be worth considering. I found a 35mm f2 Nikkor lens for $100. I have a 55mm F3.5 Macro, with an extension tube I found for, $80.
For a zoom, consider a Sigma 24-70mm F2.8 for $350. You might find it's zoom range and low light abilities very useful, since it maintains F2.8 through the whole zoom range.