There are truly thousands if not more examples of fax cover sheets out in the world. I have found just a few basic ones here:

To design or modify a fax cover sheet is easy. First, most fax cover sheets are written in Microsoft Word. To modify them is as easy as modifying any document. You can easily include your business logo, personal or business information, include your company tag line, and possibly any other type of marketing material. Maybe a current promotion, or a sample …

If you are looking for a Printable Fax Cover Sheet? They are simple to create and make brandable for your business or personality.
Here are some of the key elements to make sure you include in your Printable Fax Cover Sheet.
It should state:

Fax or Fax Cover Sheet
Your address, phone number, fax number and address
Your logo if applicable
TO:
FROM:
FAX:
PAGES (including cover sheet):
PHONE:
DATE:
RE:
CC:

Then on your printable fax cover sheet you should include and area for:

Urgent
For Review
Please Comment
Please Reply

Then an area for comments or text.
You do want to keep the Printable Fax Cover Sheet …