Clickable Images fields
Welcome to stackexchange doug! :)

This is what I believe to be the most popular solution. It's good because it's fairly easy to set up, yet very flexible. You will need the Views module.


Add a textfield to the same bundle (content type) as the one holding your images.
Create a View
Add your link field to the field list, and check "Exclude from display".
Add your image field to the field list, scroll down to rewrite results, check "Output this field as a link", and add the link "token", in the "Link path" field. The list of available tokens are listed further down under "Replacement patterns". .
Save the View, and add it where you want. :)


If you want to know more about Views, you can see a video tutorial series here.