Irish nationals do not need to apply for a work and/or residence permit before moving to Norway, but certain requirements have to be fulfilled. Please click on here for more information.
For citizens from outside the EU/EEA area, other rules apply. The Norwegian Directorare of Immigration has details on whether or not you need a visa to visit or move to Norway. Click on this link to find out if you need a visa.
Should you need a visa, please be advised that this embassy does not have any information about requirements, processing time, etc. All visa requests are handled by the Danish Visa Application centre.
Besides information about visas, work permits and residencies, this link will give practical information about various 'how-to's, like how to get a tax deduction card, Norwegian National Identity number, report your relocation to Norway, and also get information about working hours, etc.
If you wish to start looking for a job before you move, then the EURES database will be the best starting point.