We have started to build preliminary entry catalogues of potential targets for the COROT seismology programmes. In order to complete our a priori knowledge on each one of these potential targets, a vast ground-based effort was initiated to determine the fundamental parameters (T_eff , log g , [Fe/H], v sin i, etc...) of the 1,100 potential targets of the COROT central and exploratory asteroseismology programmes. We use echelle spectrographs at OHP (Elodie spectrograph), and Sutherland (Giraffe spectrograph), as well as a semi-automatic photometric telescope near Granada. We plan to complement these observations with spectroscopic runs at ESO (1.52m+FEROS) and La Palma (INT+ESA-MUSICOS). With data collected at all these sites, we are setting up a database of high (35,000 - 40,000) resolution echelle spectra and Strömgren photometric data for all of these stars. We intend to gather all of these data, as well as the determined parameters and characteristics, in a single database accessible by the community.