You need to have work experience in certain jobs, and you should apply under provincial nominee programs, not federal, because federal have limits on how many people can apply per year, and also the wait times are longer. Go here for more info
http://www.cic.gc.ca/english/work/hire/permanent_workers.asp
In general, Canada has a big shortage of skilled tradespeople, such as electricians, plumbers, construction workers, drywallers, etc.