Well, if your whites are grey, then it's an exposure issue. If your whites are blue/yellow/red/green etc....then it's probably a WB issue.
Keep in mind that to get accurate color, you should first ensure accurate exposure. Because if you try to 'fix' your exposure, the color will change.
Getting accurate WB isn't too hard. Basically, all you have to do, is take a sample photo of a color neutral object (fill the frame if possible). Make sure it's in the same light as your subject will be. Then go into your menu and find where you can set your custom WB. The D7000 has several 'slots' for WB examples. So the first thing is to choose/edit a slot, it will then let your browse to the image you just took and choose it. Then back in the WB menu, you have to actually choose that slot to be the active one. Then, back in your shooting menu, choose the 'Pre' option for your WB. All the shots will then have that custom WB applied to them. In RAW, you can still change it later, but it's nice to have it set accurately.
Or, as mentioned above, you can just include the grey card (or WB target etc) in one of the shots. Then in LR, Bridge etc., you can just use your color picker on the target, then apply that setting to all the shots that were in the same light.
On a side note about setting a custom WB. I find that on the D7000, it's not very intuitive to set the custom WB...and a few other things as well. Every time I have a student with a D7000, they have trouble. It's because with many of the options, you have to find the menu item you want, you have to select it, then confirm it, before exiting the menu. If you don't confirm/OK, your selection, it doesn't take, and you have to go back and do it again. Messes me (and them) up every time.