Images for Pinterest 'Pin It' Button

Hi

I'm using AddThis for social bookmarking on my client's blog. http://www.gilliangladrag.co.uk/blog/latest.html
I'm now trying to add a 'Pin It' button to my AddThis toolbar. The instructions from AddThis are pretty straight forward. http://support.addthis.com/customer/portal/articles/381237-third-party-buttons#pinterest-pinit

I've customised the default theme already. So all I need to do now is include the relevant code in the addthis.button.style1.php file.

The part I'm struggling with is the attributes required by Pinterest. I need to specify the image url for the image I want pinned. The page url and a description are optional. Where can I find these values?

Also how can I include the AddThis bookmarks on the teaser view(eg. Latest Entries) of the blog posts?


Thanks
Lenny