There are not too many sights
on the internet.
But, I did see this sight - it's moding in Austria. Whatever moding is...
Seriously though, this forum has the worst use of spelling and grammar I've seen in my life. Don't take it personally - it's just about 80% of the people on this forum.
Modding site. That's what you're looking for. I would just do a google search for "PC modding", "PC overclocking" you know - stuff like that. Google is your friend here.