Interesting subject; I had to read the info to find out what Tchoukball is all about. I must admit that I'm not keen on team sports, though.
Firstly, your site doesn't centre in Firefox. This is because you usually need to use tables to achieve centreing in current builds. One full width table is sufficient.
The background is a bit "in your face", particularly for those of us with high res screens who will see a lot of it. Perhaps tone it down a bit.
Your punctuation needs a bit of tidying up. The Tchoukball description in particular.
You're going to get a lot of spam from that email link. See recent discussions on how to minimise this. I now use a contact form on my sites with the addition of some extra PHP code that prevents the use of the form for sending spam.