salut sébastien et bienvenue !
i'm sure you've found already the french language forum. we've also got a german language forum, which could help you with your progress.
since you love the public domain books (so do i !) please take a look at our ebooks upload section (click the ebooks link in the blue nav bar at the top of the page). thousands of books formatted by our members, for free ! another really good site is feedbooks.com for public domain and creative commons books in all formats.
bonne lecture !