The type of water you use to make coffee will have direct implications on how your coffee will taste. In general, if the water is sufficient enough to drink naturally then it will result in a well-tasting coffee (discounting the other factors). However, there are a few methods that you can follow if you are unsure about the matter. First off, always filter your water before brewing it. A well-filtered glass of water will always taste better than tap water.
However, you may not believe this but it is better to use hard water than soft water. The reason for this is because of the magnesium and calcium present, as those are two minerals that enrich the flavoring compounds in coffee. While soft water will actually result in a flat coffee, which very few people will prefer, as sodium will not produce a quality coffee.
Also, take the temperature into consideration as that is very important. Tend to keep the temperature close to 205 degrees Fahrenheit, while not going beneath 195 degrees Fahrenheit. But, never use boiling water (over 212 degrees Fahrenheit) as that will burn the coffee.