MelanieA,
You can view census records on www.ancestry.com (which is a paid subscription site). They do offer a trial period of 14 days usually with limited access to records so why not have a look.
I would also check out www.familysearch.org . They have lots of invaluable info. Its free to use.
For ship manifests I would try www.stevemorse.org . Free database but you must register a username and password to use. The site is also amazing.
