What do we need to do to pursue an intellectual property infringement case?

We have an artificial floral design website, based in IL, USA. Each page of our site has a copyright notice at the bottom, along with our web address on our photos of our designs. It was recently brought to our attention that there is a website based in Canada that has our photos posted as their designs. They have cut our logo off of the pics, and you can actually see the tops of the letters remaining in some of them. What do we need to do to get them to remove our photos from their site and to pursue any other legal action against them? Is it different since they are based in Canada? Any help or pointing in the right direction will be greatly appreciated! - Is this your question? Add additional information