From the hardware side on a PC just plug in a card, then you will have it providing the OS supports it, as the cards typically only provide a small bios extension to just show up as hardware. The OS will have to support it, either as a native kernel driver ( best) or via an update from the OS supplier ( next best) or via a supplied driver with the card ( best not to do this, just toss the disk provided as these are going to be buggy as hell). That is all, it just appears as another USB root hub.
Cable wise you have backwards compatiability, but to get the high speed you need the card, cable, hub ( if you are wanting to use without reaching around the back every time) and devices all have to be USB3 devices. If any is not you fall back to standard USB speeds only. With an USB3 hub you can mix end devices though, like having an USB3 HDD plugged in one port and a regular USB stick in another, where you will still have high speed to the HDD.