User Activity

Does anyone know how to direct buyers to leave feedback? I send my buyers a follow up email (using the contact buyer link) a week or two after the parcel has been sent to them. But I also want to leave EASY INSTRUCTIONS or A LINK directly to leaving ...
I need help posting a photo in the description area of my listing. At the moment, it just shows up as a box in the listing. I have tried to insert the hosting url in the HTML side, but was unsuccessful. There has to be an easier way to do this. Help ...