Magnus/Roos

I have traced my family to Erik Olsson Roos, b. 1764 married to Nelia Ojarsdr b. Sept. 4, 1794. The descendancy from him goes to Magnus Ericsson Ros b. 1811 to Edvard Magnusson Roos b. June 13, 1850 to Olaf Edvard Magnussen b. Mar. 20, 1877. Does anyone know how to find more information for Erik Roos and his family? I don't know where he was born but Edvard was born in Sweden and Olaf was born in Norway, so I'm assuming that Erik was born in Sweden. Also, what does Roos mean? Thanks, Nancy Magnusson.