Here's the summary from Wikipedia:
"The series reveals that Wolverine was born James Howlett, the son of rich plantation owners in late 19th Century Canada, and has long suffered from various allergies. He is a sickly child so his loving father, John Howlett, Jr., brings an orphaned girl named Rose up from the town to be his companion (Rose is red-haired which some take as a reference to Jean Grey, with whom Wolverine sometimes showed something of an obsession). The two children also often play with Dog Logan, son of the Howletts' cruel groundskeeper, Thomas Logan (who looks a lot like the fully-grown Wolverine). This friendship is spoiled by the tension between the boys' fathers centering on James' mother, Elizabeth, who went mad after her first son, John, died under mysterious circumstances years earlier. It is hinted throughout the series that Wolverine's elder brother John Howlett III was a mutant himself with powers similar to his own. Both his mother and grandfather allude to this, and the marks on Elizabeth's chest may have come from John III's claws."
http://en.wikipedia.org/wiki/Origin_(Marvel_Comics)