I suggest a water test from Ward Lab. I sent one in, and for $16.50, you get all the information you need for brewing.
Another thing to check is to find out from your water company if they use chloramines to chlorinate the water. Those don't boil off, and are easily removed before brewing with campden tablets (available at any homebrew store). Chlorine and/or chloramines in the brewing water will ruin the taste of the beer.