Malmanger family

I am now researching information for my husband's family. Their name is Malmanger from Kvindherred, Hordaland, Norway. I cannot find the ship that Erik came on in 1901; also Johan in 1881 (I think). We have info that Johan was adopted by an Omvik family. We question if he came to America with the family and because he was only 10, for legal reasons they had guardianship of him? Is there a web site that I can locate information about the family in Norway? Thanks for your help. Carol