The 18-200 is kind of a dog. Try and avoid the 200mm end and stop down to (slightly) improve it.
You could try and adjust the D7000 focus fine tune if you think its a focus issue (is ANY part of the image sharp?) but with a super zoom like that you can set it for one end, and totally throw off the other.
Nikon D7000 dream team:
10.5mm f/2.8 fisheye
12-24mm f/4
17-55mm f/2.8
35mm f/1.8
70-200mm f/2.8
I currently use:
12-24mm f/4 - Kind of slow but very sharp. Expensive. There is also a 10-24 variable aperture that I have not used.
18-105mm f3.5~5.6 - Better optically than the 18-200 IMHO, crap build quality, plastic mount - ugh
35mm f1.8 - small, light, sharp, cheap, awesome. buy this 1st.
70-300mm f/4.5~5.6 - fast AF, but like the 18-200 suffers from lack of contrast and sharpness at the telephoto end. Might sell this and get a 300mm prime tele or the 70-200 f/2.8.
other (I mostly keep these at home and only bring along for special uses or for other cameras) :
24mm f/2.8D - not very sharp, not recommended.
35-86mm f/3.5 - wacky zoom with crap ton of ghosts/flare for vintage feel videos. Has a older coating that produces different colors than nikons newer multicoating.
50mm f/1.8E - cheap manual focus, surprisingly good but not great. VERY small pancake, almost too small to use on D7000 body.
50mm f/1.4 AI - nice manual focus lens. Use mostly for manual focus videos.
50mm f/1.4D - sharpest 50, focus ring constantly spinning in AF mode is annoying though. Use it on my AF film body.
60mm f/2.8D micro - SHARP. cheap macro. I kind of want a 100mm macro for more working distance but this one is great.
105mm f/2 DC - amazing portrait lens. Kind of long on a crop sensor, will go nicely with D600 when it comes out
