Logos
You can scan an existing logo to use on your web page. To create your own logo, you will need to use draw, paint or image-editing software.
Not all logos are suitable for reproduction on the web, especially if they
contain a lot of detail or are going to be used at a very small size.
You may have to edit your logo to be more web-friendly.
Example
Original logo is very detailed and will not reduce well:
Too small to see detail:
Modified to be more web-friendly:
Do-It-Yourself Guide
Graphics