This web site about Ellis Island is an excellent resource. It is also free to search and view the records.
One tip about registration that i have found with this site. It concerns forgetting your user name and password. If this happens, they say that they will send it to you in an e-mail. The E-mail never arrives and it leaves you having to take out another registration with a new name and user name.
Take a look at this site and read about the new Americans who arrived at Ellis Island.
Trace your own Ancestors through the Passenger lists.