The regulations and formalities depend on whether you wish to:
If you want to clear your vehicle within Switzerland (i.e. not directly at a border crossing), you must ask Swiss Customs at the border for a temporary certificate form 15.25. You can get this at all manned border crossings during opening hours in tourist traffic. With the temporary certificate form 15.25, you have two working days to declare the vehicle at a customs office responsible for merchandise within Switzerland.
Use of Swiss motorways is subject to a tax. More information can be found at Motorway tax sticker (vignette).
Information on the heavy vehicle charge can be found at Heavy vehicle charges (performance-related and lump-sum).