NavyWife, it's a great camera. Glad you got one!
Lighting with this camera can be difficult - if you are referring to the built in flash unit. Like any other camera, straight on flash will result in occasional ugly pictures. You may want to budget for the Nikon SB600 or SB800 flash units. Digital is very sensitive to supplementary light, but these flash units are perfectly mated tot he camera. If you want to see a dramatic improvement in your images, try bouncing the flash off the ceiling (assuming you have white ceilings). Using a bounce card outdoors will also help tremendously in some cases.
As for focusing, what lens did you get with the camera? Did you get the 18-70mm kit lens supplied ny Nikon? It's usually quite fast to focus. The AF-S helps a little. Also , you need a bit of contrast to lock onto your subject. For instance, focusing on a white snow scene may make the lens hunt, or if the scene you are shooting in is dark you may have some trouble. Since I shoot people all the time, I usually lock onto their eyes, the hold the AFL/AFE button down on the back of the camera, recompose and shoot. Once you learn the method, it takes half a second to nail it.
Finally, if you are seeing items slightly behind your subject in better focus and your main subject is soft, your camera may have a back focus problem and may need to be sent back to Nikon for recalibration. The way to determine this is to shoot a newspaper against a flat wall using a tripod. If you think you have the text in focus but your image shows blurry text, then you mayhave a problem. It's a very rare problem with the D70S, but it was common with the first generation D70 bodies when they first hit the market. I noticed it in one of my friend's D70 bodies when I photographed a bride against a roman column. She would be slightly out of focus, but texture of the column slightly behind her would be razor sharp. The body was immediately replaced. My D70 bodies and my D70S never exhibited this problem.
Your lens can also be the culprit. What lens did you get? Nikon? Sigma? Tamron?
Finally, most D70/D70S images need a boost in contrast and a bit of red pulled out of the image to give you a decent starting point. It's all personal preference. Every camera has it's quirks.