How to search for Schlesisch Ancestors?

I’ve found a few ancestors on Szukaj w Archiwach.

Most of my ancestors lived in Leutmannsdorf, Nieder Wüstegiersdorf and Neurode in Niederschlesien, Prussia (today Lower Silesia, Poland). These records are available from the late 1800’s. But I’d like to explore earlier generations and research beyond.

Is there any websites and research strategies that anyone could recommend?