First you have to be sure you have the software level that supports tethering and/or mobile hotspot. Patch came out about 6 months ago if I remember.
The easy way is to turn on the mobile hotspot and use wireless to attach your PC. Otherwise you can use a USB cable but you may need a driver for your PC since it appears as a modem.
The big IF on this is if your provider allows it. The phone may have the feature but the provider may charge you to activate it. This really varies greatly from vendor to vendor. Few if any vendors will allow UNLIMITED internet when you are running a PC on it. You will need to read the fine print to see what they mean by unlimited.