Here is some stuff that should help out..
Here is an excellent sticky on matching your water to the style you're brewing.
http://www.homebrewtalk.com/f128/brewing-water-chemistry-primer-198460/
Basically as follows:
Baseline: Add 1 tsp of calcium chloride dihydrate (what your LHBS sells) to each 5 gallons of water treated. Add 2% sauermalz to the grist.
Deviate from the baseline as follows:
Hefeweizen: For soft water beers (i.e Pils, Helles). Use half the baseline amount of calcium chloride and increase the sauermalz to 3% (you can make great Hefe with soft water too).
Porter: For beers that use roast malt (Stout, porter): Skip the sauermalz.
Light Ale: For British beers: Add 1 tsp gypsum as well as 1 tsp calcium chloride
IPA: For very minerally beers (Export, Burton ale): Double the calcium chloride and the gypsum.
Pilsner or soft water styles: 1/2 tsp calcium chloride, 3% sauermalz
American Pale Ale: 1 tsp calcium chloride, 1 tsp gypsum, 2% sauermalz
British Pale Ale: 2 tsp calcium chloride, 1 tsp gypsum, 2% sauermalz
Hoppy/Strong British Ale: 4 tsp calcium chloride, 2 tsp gypsum, 2% sauermalz
Porter or Stout: 1 tsp calcium chloride (no sauermalz)
Cascadian Dark Ale (hoppy): 1 tsp calcium chloride, 1 tsp gypsum (no sauermalz)