I would suggest that for the times you are "IN" Canada but travelling (address: friends place), you can say you were looking for a job.. You have to count the days you were in Canada since it will show you are in Canada by your passport entry stamps. By not declaring those days would trigger RQ for you and would mean you have to present a lot of documents to prove why you were in Canada.
June xx, 2010 – June xx, 2010 Canada
June xx, 2010 – April 02, 2011 Home Country
April 02, 2011 – Any date you were in US..
Any date you were in US – Present - Canada