100 ISO as your first port of call.  Dont stray from it unless you have to compromise because of light strength.

As for sharpness - what Bruce says above is true - if that doesnt get the look you are going for you should try some post processing steps.  I posted up a tutorial which touches on sharpening (and generally contrast) which you might find helpful (it does assume you have photoshop):

http://www.renderosity.com/mod/tutorial/index.php?tutorial_id=2056

"In every colour, there's the light.
In every stone sleeps a crystal.
Remember the Shaman, when he used to say:
Man is the dream of the Dolphin"

Rich Meadows Photography