The Wyeast package recommends making a 1.020 SG wort and pitching the active contents of the package into a sanitized bottle with an airlock to allow the quantity of active yeast cells to build up before pitching into a typical 5 gallon batch of wort. This "starter" wort is usually made from dry malt extract boiled with water at the rate of 2 tablespoons per 8 oz. cup of water. Some brewers like to throw in a couple of hop cones or pellets for their antiseptic qualities. When the starter is at high krauesen (the term is used loosely here, you often won't get a foamy head on your starter, look for visible, strong fermemtation) it's ready to pitch. Typical time for a starter is 24 hours. This technique is recommended for both dry and liquid yeasts.