First open up Quicktime Player from your Applications folder.
Click on the "File Menu" and the "New Screen Recording" or hit Control-Command-N.
You’ll get a little black Screen Recording window from which to control your options and start recording. When you click the drop-down arrow, you’ll see even more stuff you can change, including the location where your movie will be saved.
Make sure to toggle the “Microphone” option off of “None” if you’d like your viewers to be able to hear you talk while they’re watching your video.
“Show Mouse Clicks in Recording”—is an especially helpful new feature in Lion. With this, clicking on something during the recording will make a small circle appear briefly around your cursor to give your audience a visual cue about where you’ve clicked.
Another shiny new plaything is the ability to choose an area of your screen to record rather than having to make a video of the entire thing (as was the case in Snow Leopard). When you click the record button, here’s what QuickTime will tell you all polite-like:
So drag to select an area that you’d like to record, and then when you release your mouse button, you’ll be able to resize the box you’ve made by dragging the familiar handles around it. You can also click and hold on the interior of the box and drag to adjust its position on your screen.
When you’re satisfied, click “Start Recording,” or you can hit Escape to exit out of the box-adjusting window if you don’t want to actually record anything.
After you’re finished making a Video, click the stop button on the black Screen Recording window. QuickTime will then process your work and save the .mov file to wherever you’ve assigned it to do so. Using the “Share” menu option, you can publish your Video to YouTube, send it directly to an e-mail, or even put it on Facebook.
