Great camera choice!

As for settings I'd start with:
ISO 400
Dial set to S (shutter)
Play with different shutter speeds until you find your groove.

The kit lens is ok. The a100 uses Minolta Maxxum lenses. You can get them used for cheap and they are great! I recommend the minolta 35-105mm (also known as the beer can) to start. You can get it for around 50 bucks. Here is a site I live by for lens reviews and info

www.dyxum.com