I have several individual pictures of my 4 dogs and I want to pick one of each and put them all together on one photo
The easiest way to do that is to select your photos and create a collage out of it. You can find more detail about making collage from : http://helpx.adobe.com/x-productkb/multi/create-collages-montages-photoshop-photoshop.html #main_Create_a_collage
which version of operating system and pse are you running?