I've signed up for the 14 day trial at ancestry.com, and using their resources, I have traced my lineage through my mother's side into the 1580's in Germany and Switzerland, and into the 1660's in Prussia.

However, my father was adopted, and ancestry.com has no information about his adoptive parents, or his biological parents. I do know a little bit: I know his biological mother's name, and I know the history (to a few generations, anyway) of his adoptive parents.

But, I would like to know more. Do those of you who've done lots of genealogical research have any advice for finding out more about my father's background?