How to choose a specific thumbnail photo on like button

I have a webpage i keep adding a like button app to but whenever i click like i get some random member phot of a lady on facebook representing my page. this is frustrating.

I 开发者_运维问答find all this html script and i cant seem to put it together properly so will you just please give me a simple paste ready like button formula with a set specific thumbnail photo that I can choose to represent my own page?

Use the open graph properties for your webpage defined here:

http://developers.facebook.com/docs/opengraph/