Putting motors and wheels on a robot

I am building my first robot so im new to this. I have all the electronics down but Its the motors and wheels that bother me. I found these wheels and I need to 4 of them (gonna order twice) However how would I fit into a DC motor or connect it to the chassis of my robot (the chassis is just a plastic rectangle with the arduino and other stuff on it). Also when I looked up these wheels they have a special geared motor to them and a mounting hub, is this what I use for the wheels??

Mounting hubs connect motors to the chassis, usually by using screws and/or bolts. Wheel mounts are a little more tricky as there a lot of ways to do it. Try googling or using some specifically designed for your motor/wheel combo.