There's not only one option as to what you can use to record your facecam. If facecam drivers exist for your camera then download them (drivers like these turn your camera into a webcam, but you have to have it connected to your pc). If drivers like these don't exist for your camera, you are going to need to buy a webcam, even a cheapone will do (l have a Microsoft lifecam-3000 and it records 720p 30fps.) It is most likely that the webcam will come with a cd with the drivers. If it's a microsoft webcam you'll be able to record it using movie maker, as well. You are also going to need a software that records your gameplay (if you have an nVdia gtx gpu then you have shadowplay, if not there are many other programms like fraps, dxtory, bandicam etc.) Once you've recorded your gameplay and your webcam you'll need to put them together into one video. To do that, you are going to need a video editing software that suports multi-layer editing (personaly use premiere pro cc, also l'm not familiar with iMovie, but if it allows multi-layer editing it will do the job). Oh and by the way, you'll need a microphone and if you want to record your console (playstation, xbox, wii) you are also going to need a capture card. l hope my information was clear, if you have ANY questions let me know.