Use IrfanView to resize your pictures. It is very easy to use. Open the picture select Image -> Resize Resample and select 800 X 600. Save as, then attach.

Or if you have a picture online, simply click this button and paste the URL of the picture in.

Or, as mentioned, upload to Flickr or Picasa and supply a link.

Prices and pictures.

Without this it's a bit like saying 'I have something for sale, anybody interested in buying it?'