First, put a bottle top, extra end cap, something thats white in your tank (temporary) under the lighting you plan to shoot in.
Second, take a picture of said white object, filling as much of the viewfinder with it as you can.
Third, go to you white balance setting and select custom, then use picture, then select that picture you took of your white piece that you dropped in the tank.
Now your white balance is set to your lighting.
as far as close-ups go, go to your local photo shop, and pick up a close up filter, usually no more than about 30-40 bucks. This will allow you to get MUCH closer shots with minimal distortion until you can drop some coin on a true 1:1 macro.
When you decide to buy a macro lens, i highly recommend the Tamron 90mm macro. Out of my 3 macro lenses, its my favorite.
Now, for setting of the camera, keep it in manual, and learn to use your exposure meter. the higher the F-stop (aperture) the longer depth of field you will have (how far beyond the first part in focus that will remain in focus. Dont worry, if you use say f22, you will not see everything in focus that will be in focus. Using manual focus and tripod, focus in on the absolute closest part of the subject you intend on photographing, and everything beyond that will be in focus (how much depends on your f-stop).
Once you've decided how much depth of field you need, you can dial in the shutter speed. watch your exposure meter, and once its 1 bar into the negative, you are ready to fire. Always better to under expose with digital, the opposite is true with 35mm.
Now, ISO, the slower the ISO speed, the less grain you will see in your photos, but with slower speeds, come much longer shutter speeds. This is why you need a tripod. Try to use as low of an ISO as you can.
When shooting your pictures with long shutter times, you will notice a blur just from the vibrations of you pushing the shutter button. either spend 30 bucks on a shutter release cable, or use the shutter timer. you can adjust it to delay 3-10 seconds on the d70 i believe, i like 5, it gives enough time for the camera to stop moving, and then it will fire. This way you aren't touching the camera when it fires, thus eliminating the blur.
Those are the BASIC settings to play around with, these are what works for me the best, but there is plenty of room for experimentation, thats the beauty of digital, no wasted film, just a delete button, and re shoot.
HTH,
JuniorMC8704
