How to make Signatures

[Sierus]

First; Upload it to a imagehosting site such as : http://imageshack.us/

Then get the URL of the uploaded image, provided by the hosting website

Then finally once ammending your signature, click the "Insert Picture" button to the left of the Insert Hyperlink button,
Put in the URL of the image and then click okay, save the changes and voila!

Hope this helps.