So you would like to learn more about the different types of ingredients used in brewing beer. Brew Your Own Magazine (BYO) has some very useful pages on this. I have listed them below with some information of what you will find when you go to each page.
Here’s a composite list of grains and adjuncts. The color is listed in degrees Lovibond and the gravity is calculated from 1 pound of the ingredient in 1 gallon of water. Click on the link to begin.
Grains and Adjuncts Chart
To select the hops for your brew click on the link, then select a beer style and a chart will display the appropriate hops to consider for your recipe.
Comparing and Selecting Hops
There is also a good article on Wikipedia as well describing the different hop varieties. It can be found at Hops.
To learn about some of the most common strains available click on the link, select a beer style to view a chart with appropriate yeast strains to consider for your recipe.
Yeast Strains Chart
For a yeast strain comparison chart you need to go to Mr. Malty’s Yeast Strain Comparison Chart