The ESO Key-Programme ``A Homogeneous Bright QSO Survey'' - I The Methods and the ``Deep'' Fields by Cristiani, S, Franca, F, Andreani, P, Gemmo, A, Goldschmidt, P, Miller, L, Vio, R, Barbieri, C, Bodini, L, Iovino, A, Lazzarin, M, Clowes, R, MacGillivray, H, Gouiffes, C, Lissandrini, C, Savage, A