Can't decide what to brew???
Lagers are a common variety of beer- most American "beer" is officialy lager. By definition, lagers are bottom-fermented beers, which means the yeast does its thing while at the bottom of the fermenting container. Bottom fermenting also requires reduced temperatures to take place. These beers are light and crisp.
An ale, as opposed to a lager, is top-fermented, which means the yeast boils away at the top of the beer wort as the beer ferments. Ales are often fermented at temperatures just below room-temperature. There are a great variety of ales, including pale ale, brown ale and India pale ale. India pale ale contains excessive hops, as hops are a preservative and it was historically brewed in this manner to survive long trips around the world. The excessive hops make it quite bitter. Pale ale and brown ale are less bitter and vary in character, but like all ales are flavorful and refreshing.
A dark, generally low-alcohol brew that is made by the top-fermenting process. The color comes from dark-roasted malts used in the boiling of the wort. Stouts are often quite creative; brewers often empoly sweet milk sugar, cocoa or fruits to flavor them. Stouts are less bitter, subdued and often have a "roasted" flavor.
Somewhat like a stout, this beer is dark and often sweet. Porters take a long time to mature in comparison with other styles, so patience is required.
A light-colored style originating in Germany, the pilsner is often quite hoppy (bitter) and dry. Pilsners are bottom-fermented.
(thanks to Michael Jackson and Beerhunter.com for info)