Norms and stimuli for timed picture naming in seven different languages (American English, German, Mexican Spanish, Italian, Bulgarian, Hungarian, and the variant of Mandarin Chinese spoken in Taiwan) http://crl.ucsd.edu/~aszekely/ipnp/index.html
CELEX Database for word frequencies in English, Dutch and German: http://celex.mpi.nl/.
Its use is quite complex at first. Ask me if you have trouble. There is a "how-to" on the intranet too.
Here is the user guide in English, and in German
LEXIQUE Database for word frequencies in French: http://www.lexique.org/. Much easier to use, but mainly in French. It has a useful Google translate button.