just to let you know ...
https://passionford.com/forum/viewtopic.php?t=106240

Here are the allowable sizes:
Max siggy physical Size: = 550 x 150 pixels
Max siggy Disk size: = 25600 bytes (25k)
Max Avatar size: = 105 x 105 pixels
Max Avatar Disk size: = 5120 bytes (5K)
Max Text size: = All text printed in the signature area must be normal font size.

if you have a picture you want to use but is over the allowed sizes ask in the photoshoppers forum.
there are some great people in there who are good at all things picture wise.

you have to upload the picture to a site , most use www.photobucket.com or you could use www.tinypic.com but there is an uploader facility on passionford on the bottom left hand side.

just upload the picture and add the resulting line of text into the signature box in the bottom of your profile..
but you need to have [img] at the front and [/img] at the end.

hth