Can any one give me a good website where I can safely trace my family tree without having to pay or something?

[Dominic II]

Alright, so far I can trace my family tree on my father's side back to 1791, when a great-great-great-great(?) grandfather was born. He became the Postmaster General of County Kerry.


I'd like to figure out more about my ancestors, but I don't want to pay for it or to have to give personal info or stuff like that.

Thanks all who give good answers!
The Postmaster General's name was Dennis Thomas Downing.