Laural:
As I mentioned above the Houlihans lived in Lyrenageeha townland in Inchigeelagh civil parish which is near the Co. Kerry border. Lyrenageeha was 484 acres in size. If you have the Google Map application enter Lyrenageeha and you will get an idea where it is located.
I'm not sure you will find a baptismal record for Jeremiah Houlihan or Mary Swiney. There were no baptismal records in iveleary for either name and I did not locate the marriage record. Also, without knowing their parents names how would you conclusively know you had the correct record.
Since they did live near the Kerry border, I will look for a marriage record in Kerry.
The earliest full census available for Ireland is the 1901. There are a few fragments from earliers censuses but none for Inchigeelagh parish. I checked the 1901 census for Lyrena geeha and there were no Houlihan families.
You won't find any Irish records on emigration from the country. Your best bet is to use Ancestry or Familysearch to see if you can find him coming into the USA.
You asked about web sites. www.irishgenealogy.ie is a good site for part of Co. Cork as well as Co. Kerry. The Mormon site www.familysearch.org is a good free site. Ancestry is a subscription site but very useful and there are other subscription sites in Ireland which can be helpful.
Roger