To create your first cover letter, click the “Cover Letter” option in the left bar. From there, you can click the "+Add a new cover letter" link just under that, or the “Build your Cover Letter” button in the middle of the screen.
You will begin by choosing a template from the available options. From there, you will be shown your cover letter, with placeholder text in the body. Click on either the body to edit the message or the top of the cover letter to edit your contact information.
You can also click the "+Add a new cover letter" link to create additional cover letters. When you have more than one cover letter on your account, you can scroll through them along the left hand bar, under the option to add a new file.