If the profession the employer is looking to hire is among the federal skilled workers 38 professions (i am not sure carpenter is there or not), then the employer doesn't need to do any thing (Assuming he is not in Quebec). If he is in Quebec a document called CAQ (Certificate of acceptance for quebec) is required.
If the profession is other than the list, then employer needs to apply for LMO(Labour Market opinion) in Canada. There are associated application forms and fee and employer must show to Canadian government that they tried filling the vacancy locally but couldn't so they intend to hire a foreign worker. There are two types of LMO's. In one, the name of employee is mandatory along with other details such as his passport, date of birth etc. The other type of LMO does not have employee's name and employer can fill that latter.
It takes any where between 6 weeks to several months in getting an LMO.
Once employer has it, he can send it to you (electronic copy is fine). You would then apply to your local embassy for visa along with this LMO document and job offer.