Do you pay income tax on both sides of the border?

I am and American citizen & a landed immigrant in Canada., for over 20 yrs. I have just started to collect. the Cdn . Canada Pension, Old age Security & Social Security Income from the U>S>A> .I plan on still working. Do I have to claim all of this income to both countries. or just the SSI to the American income tax and just earned wages & pensions to Canada. How much can I earn before a clawback from both countries?