Writing contests can be a good way to get your writing polished and also become more known (especially if you win). Also, if they are held by a magazine then often you end up with a subscription too which is nice. Beware of contests which require anything of you other than the entry fee and also which are not associated with a reputable publishing company or magazine.
Here is a list of contests I've come across or sent stuff in to in the past. Feel free to let me know of any more.
http://www.3daynovel.com/
http://www.geist.com/contests
http://www.malahatreview.ca/creative_non-fiction_prize/info.html
http://this.org/contribute/great-canadian-literary-hunt/
http://www.writersunion.ca/cn_main.asp
http://www.freefallmagazine.ca/contest.html
http://www.radio-canada.ca/prixlitteraires/english/
http://arcticamag.ca/current-issue/1-today/70-writing-space-contest.html
Good luck :)
