I recommend that you start with the first page and gradually work through all of my pages, starting with "The Athletes" page to the "Wrestling and Boxing" page. I have provided links to other good sites about the ancient Olympic games. Also if you look in the "Bibliography" page, you will find other good resources to use as reference to get a more in depth look at the games.
I thought of a few activities that you can assign to your students. The diorama project does take quite a bit of time, but in the end, the result is really fun. I have found that I really have to research my topic for a diorama so that my diorama would accurately depict what I was trying to make. This is a great project during the long breaks. The mock wrestling match is supposed to be a NO CONTACT skit. You don't want the students to get hurt. For the ceremony project, students could either do this in groups and do a skit, make a video or just write a description. This is up to you. The last project is just an essay. Be creative. These are only a few suggestions, but it is a start!