Hi Victor and welcome to ReactOS!
In general, I'd recommend you to join the #reactos IRC channel for getting help (see http://www.reactos.org/en/community_mailinglists.html). There are always >100 people online there, so you should get answers there faster than here on the mailing lists.
To answer your questions:
When reactOS will be NTFS compatible?
This is a frequently asked question and it's answered in detail here: http://www.reactos.org/forum/viewtopic.php?t=2487. In the meantime, someone already started working on a ReactOS NTFS driver, but anyway the kernel is still not ready for it as described in the forum post.
Can I translate it to my native language?
Yes, this is possible.
As you come from Brazilia, I assume your native language is Brazilian Portuguese, right? We have a few Portuguese translators, but not as many as for other European languages, so we could really need some help here!
It's possible to translate parts of the code and also the Website to another language. If you want to translate the code, download the current trunk version using an SVN client (see http://www.reactos.org/wiki/index.php/Subversion), add your translations and then submit a patch with your translations (see http://www.reactos.org/wiki/index.php/Submitting_Patches). For translating the Website, please ask someone at #reactos-web if he can give you Translator membership for your account. Then you can easily edit all pages with your RosCMS account.
Can I do(or try) some artwork for the project (or to promote it)?
For all questions concerning artwork, please ask "mf" in the #reactos IRC channel. He does most of the graphical stuff so far.
Best regards,
Colin Finck