To start, use water labeled as distilled or sterilized. To use tap water, boil it for several minutes and then let it cool until it's only slightly warm, called lukewarm. If you can't boil water, you can use tap water that's been passed through a water filter. Filters may be labeled in a few different ways. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.