It's not really accurate and can be quite funny to read but most of the time we can get the point
Anyway, to start with go to your user panel:
http://www.aquilerosanero.com/forum/usercp.php and click on "Modifica le opzioni" under "gestione e opzioni" tab. At the bottom of that page you can see "linguaggio del forum" there you can choose English US. That should fix and translate most part of the forum (it comes out in English so you should have no problems at all). Of course you won't be able to see the posts in English
but it's still helpful
P.S.: after you've chosen English (US) language you can go back to your user panel and change everything you want
P.P.S.: you can try
http://babelfish.yahoo.com/ but I haven't really used it from english to italian so i don't know whether it's good or not. You can also use this great dictionary
http://www.wordreference.com/ to translate single words and it's very very accurate