Hi,

My domain name is www.inter-tra.***
I'm building a website for free css (and maybe simple html) designs,
do you think that the domain name matches the future content of the website???
and is it a good idea to put free css designs that I have made?
Thanks

There are already tons of free, open-source CSS designs here:
http://www.openwebdesign.org/

If you're designs will be semantically correct, completely valid, and at least HTML 4.01 Strict.. or better, XHTML, then have at it.

Afraid I don't see any correlation between free CSS designs and a domain name of inter-tra.***

I think about: internet training as a title
it will contain valid css and xhtml design, and tutorials

does it seem more compatible in your opinion?

"Internet Training" sounds more like 'how to surf web' more than page design and tutorials.