On your League Home page, the header displays several links. The third link from the left is "Trophies". Clicking on that link will take you to your league's trophy page. Here you will see your league's trophies listed in chronological order, as they are assigned.
You will also be able to view "Trophy Leaders", which displays which team has received the most trophies and "Trophy Catalog", which showcases the trophies available for your league.
The League Manager will also have access to links for creating and assigning trophies.