1 - According to Environment Canada's "National Climate Data and Information Archive", the record for most snowfall in a day was set March 2, 1947, with an accumulation of 40.6 cm. In comparison, Sunday's snowfall (according to the CBC's website) set a record for the most snow in a day for the month of December, with 38cm.
2 - I have not been able to find any authoritative information regarding the most snowfall in a year. An article in the Ottawa Citizen of December 14th states "...record annual snowfall of 435.36 centimetres, which was set in the winter of 1970-71.", but does not give a source for this data. Environment Canada provides a yearly average snowfall of 235.7cm for Ottawa.
Related: Ottawa Weather Guide