Dear Computer Fairy

I know there's a way to do this, but I don't how.

1) I want to record some training videos and post them to YouTube.

2) I want to use my laptop's camera to record myself.

3) I want to be able to switch screens with pre-loaded graphics where my voice continues to talk over the switch in what is displayed, seamlessly.

4) Each video would be about seven minutes long. After recording, I need to post them to YouTube.

What program do I use? What hardware do I need? How do I go about it?