Genealogy / Seeking information about the last name Lebida or Janus. [8]

I am seeking information about the last name Lebida or Janus. My grandfather was from Lodz, Stanislaw Lebida. My grandmother, Agnuska Janus I am not sure of her origin of birth. Does anyone have any information about how I would go about finding more information on these grandparents, and any living relatives?