Moving over to a mac from windows and one feature I really enjoyed was being able to map my scroll up and scroll down keys and (+) and (-) respectively.
Then, while in a web browser or picture preview I could hold ctrl and scroll up and down to zoom in and out.
I have been having trouble implementing this for my mac. I tried the better touch tool but can't seem to make it work with that.
I also tried System Preferences->Accessibility->Zoom to change the settings there but it does not increase the size of whatever I am viewing, it just actually zooms in the entire computer screen (which is an unwanted effect).