You can customize your event page by adding images and video to your event description. Here's how:
1. From the Event Control Center for your event, click on "Edit Event Details":
2. Scroll down to the "Description" section
3. To add an image, click on the image icon:
Enter the URL of the image that you want to add, and set any properties. If your image is not already online (ie it's on your computer) you'll need to upload it. If you need a free image hosting service, TinyPic is a good option.
For video, click on the video icon:
And enter the details of the video you'd like to embed:
Flash-based or HTML 5 based videos should work just fine.
If you're having trouble embedding your video, you may want to switch to HTML mode to manually enter the HTML video code: