What is eagle.cad? Eagle.cad is a pcb design software.
Step 1: Starting new project & adding components
After that you should have a new window pop up. This is were you are going to draw your schematic.
To add a component you need to click the add button. Then find your component. Click OK and you should have the schematic sign of your component, just click and it will be added. That I show you add a part. Keep doing that Intel you have all the parts you need. To turn a component all you have to do is right click.