Resources useful for researching a family tree.
(individual surname, state and country message boards)
(message boards, etc.)
ISTG (Immigrant Ship Transcriber's Guild)
Castle Garden (New York port used before Ellis Island)
Family Search (the Mormon Church's new database)
(surnames by state and county)
(New York port immigrants came into from 1892-1924)
SSDI (Social Security Death Index)
(I've never found anything useful on it but some people swear by it)
Has sources you can't get elsewhere but you have to pay for it.
The Sidney library has it for free on one of their computers.
County courthouses, local libraries and churches.
State vital records. Every state has a website where you can find out
how to access records.