There are many different varieties of hops, each giving a particular beer style characteristic and aromas. Malted barley is the main ingredient in beer. It is the source of the fermentable and non-fermentable sugars that makes beer a malty, alcoholic beverage. Malted grain must be mashed in order to convert the starches in the grain to the sugars that brewers want. As a beginner, you will probably use malt extract where the mashing has been done and the sugars are condensed for convenience.
Malt extracts are available either as a syrup or a dry powder.
There are many different types of malted grain that include pale ale, pilsner, chocolate and caramel. The American Homebrewers' Association homepage with classic recepies created by brew professionals. Contains the latest news on homebrewing. Also has many links of interest, including instructions on the most popular beer drinking games.