Just need some advise.
I landed in canada on my wifes(shes a canadian citizen) , spousal sponsorship visa Last August 2008 and returned back to U.K without getting a social security number.
I having been living in the U.K since then with my canadian wife and have a regular job here and paying tax here/
We will only move physically to canada once i Have passed my professional Medicine Exams.

My question is do i need to do tax returns for canada despite not having lived there or having earnt any money there and what is the procedure to tell the revenue there that you are not living there

thanks

http://www.cra-arc.gc.ca/tx/nnrsdnts/menu-eng.html
Clearly you are not resident, but if in doubt there is this form.

http://www.cra-arc.gc.ca/E/pbg/tf/nr73/nr73-08e.pdf

Many thanks so much.
Another related question , in the light of the above, When I landed last Aug the exchange rate was quite high, nearly $2 to the pound. I didn't transfer any money over at the time , but am planning on transferring quite a bit of

money when i actually move next year. If the exchange rate is different would i be paying any tax on the difference in exchange rates.

Thanks again

No. You don't pay any tax in Canada until you become tax resident here. You don't become tax resident until you move here to live.