There is a great deal of investigation that can be done using the Internet. Of course you have to start with basic identification of the persons you are seeking. Their names, years of birth, years of immigration to America, and helpful would be the names of other family members and basic dates for them too.
Others on these message boards might be able to help you get started if you can provide information about your immigrant ancestor(s) and post your query/request for assistance on message boards where large numbers of experienced researchers of Norwegian persons read and respond if they think they might be able to assist.
Preparing a good query to post -
http://www.rootsweb.ancestry.com/~wgnorway/good-queries.htmGood message boards to post on -
http://boards.rootsweb.com/localities.scan-balt.norway/mb.as...Excellent basic information about researching Norwegian ancestors. Much more information is available online since these articles were written - but it is always good that you have a basic understanding of what records are available, Norwegian naming patterns and practices, etc.
http://homepages.rootsweb.ancestry.com/~norway/articles.html