Translating WineHQ requires some comfort with the terminal.

The procedure for updating the website (eg adding a translation) is to check it out from git (git clone http://source.winehq.org/git/website.git)

Then you translate individual pages located in templates/en and place them in templates/xx (where xx is the language code). Then you make a series of git commits (one per page is probably good) - put [lostwages] or [website] at the start of the description so it's easier to tell apart from other patches. Finally you make a Git patch set and send them in to the wine-patches@winehq.org mailing list.

For help with Git check out GitWine