Hi, thanks for considering to do this. Awesome

I've moved your post here, to the translations forum.
You can find the .odt sources files here:
http://www.linuxmint.com/documentation/user-guide/. Start with the file "english_13.0.odt", and you can translate it using LibreOffice or another program that supports .odt files. LibreOffice will also allow you to publish the .odt file as a .pdf file. Once you have translated the document and are satisfied with your translation, please make the files available for download somewhere so we can add them to the Linux Mint website. Perhaps also post in the Italian forum (
viewforum.php?f=65, or the local community
http://www.linuxmint-italia.org/index.php?action=forum) that you are going to do this, to perhaps get others involved for reviewing or helping with the translation or replacing the English screenshots with Italian screenshots.
In this forum you can find from the past few months other users that contributed a translated User Guide. Like from this post:
viewtopic.php?f=43&t=105667