The best pleace to get off the city for southern destination (Piotrków Trybunalski, Częstochowa,Katowice, Bielsko Biała ,Cracow, Wien, Bratislava) is bus stop next to hospital of "Polish mother" (MATKA POLKA). You can go there from the center by bus 70 (40min from train station ŁÓDŹ FABRYCZNA).
To get off for northern destination (Warsaw) is "strykowska" road. good luck!