If you wish to build a fence, you do not need a permit to proceed if the fence is less than six feet high and in a residential neighborhood. You should also be sure of your property lines before you proceed. Check with your neighbors and be sure you are not infringing on any of their property. In addition, fences may not be placed within the sight distance triangles.
As for decks, a permit is required per the International Residential Code. Please see the Residential Packet (PDF).