USA Work Visa Guide & Assessment:

United States offers its visitors and residents with a multiple and flexible choice of visa for working. You could belong to any field, or have any specific expertise, but you will not be allowed to undertake work without legal permission. If you belong to Canada then it is rather easy for you to acquire a US work visa, due to the various agreements and treaties between the two countries.
Immigrant or Permanent Worker:
Having an immigrant visa or the green card, you can stay and work in the US indefinitely. You need to be an individual of outclass intelligence and talent to earn this work visa.
Non-immigrant or Temporary worker visa:

The non-immigrant or temporary visa is available under the H1B or the H2B category. The H1B category is for people in specialized fields with high technical expertise like a graduate’s degree. The H1B visa can only be applied for by the company or organization who is hiring while the H2B visa is to be applied by the individual who is willing to come to the United States for temporary work. He cannot belong to the field of agriculture. The maximum validity period is one year for the visa.
The L1 visa is also a nonimmigrant visa. The visa enables companies inside or outside of the US to carry out specific employee transfers to the US. Managers and Executive level employees and specialized knowledge Staff can be transferred under this visa. The maximum time period is for seven years, which starts with a three year visa and can be extended.
J1 visas are issued to foreign doctors for practicing in the United States.
TN1 visa is for Canada based specialized professionals, with the employer being based in the US. A huge range of professionals like accountants, hotel managers, urban planners, scientists and a lot more can take advantage of the TN1 visa.