Here's a link to a talk by William Dunham on Euler. It's only an hour long and all of you should find it interesting. The first half covers Euler's life and main accomplishments, and the second half covers a detailed (but accessible) proof of one of his results.
One of Euler's discoveries that Dunham covers is about the Euler Line. This is a fundamental property of triangles that no one discovered for thousands of years until Euler. Here's a link to an interactive website where you can create your own triangles.