Ok, So I got a D100 (its actually my GF's)

She has two lenses:

a Sigma 70-300mmD Macro
and
a Sigma 28-90 mmD Macro


Ok, So, I finally got the camera to take pictures I could see..

What are the best things for these two lense like distance.

And I need help getting these settings. I should be able to take decent shots with this camera. Some one give me some pointers please