First off click on Encyclopedia on the menu. You should see the following.

Click on the category you wish to look at. You will then see

Click on the letter you wish to look through. You then will see a list of terms starting with that letter. Click on the one you wish to view and you will be shown information.

You can click search and search for a certain term if you wish. If a term you know is not listed, you can click add term and add the term.

On the other hand you may click Main Index and be taken back to the list of categories.