What Lens would be good for Nikon D-70 Camera?

I need to take close up *Micro* Pictures. Eg. The markings on a piece of Jewerly.

Look at the Nikkor AF-S 40 mm f/2.8 macro lens

A Tamron 90mm f2.8 macro lens should do it.
This is how it shoots a watch on my different brand APS-C sensor camera.
http://www.pbase.com/johnfr/image/55928668

Any macro lens, or as Nikon calls 'em - micro, will be excellent choices. Or, save a lot of cash and just use an extension tube with your current lens.
Depending on how you want/need to light the jewelry, you will need different focal lengths. All true macro/micro lenses will give you a 1:1 reproduction. That is to say that the size of the image being projected onto the film/sensor will be the actual size of the object being photographed. The difference then between a 50mm, 60mm, 90mm, etc. Macro lens is the working distance. You will be much closer to your subject with a 50mm Micro than with a 100mm Micro. Both lenses will produce the same image, but with the 100mm you'll be further away which allows you to place your lights while not casting shadows onto your subject.
Take a look at http://www.photozone.de/...e/nikon_ff to see how the various macro/micro lenses perform. The Tamron 90mm is a legendary performer at a very good price, and it makes for a great portrait lens too.

Sigma makes a very good 70mm f2.8 macro. It requires an autofocus motor in the camera, which your D70 has. However, when the time comes to replace it, that can limit your options of what new body will autofocus with it. A D7200 would be fine with it.
The Micro Nikkor 60mm f2.8 AF-S would be a good choice, and it would be able to autofocus with a D5500 or similar if you want to get one later. A very good choice for portrait lens, too.
Whatever macro lens you get, you want a good tripod with tilting or reversible column. Also a good external flash. A macro ring flash could be ideal, but a general use flash as bounce flash can work for you.