I have downloaded Photoshop 11 on my mini Mac system. The problem is when I go to open a picture from my photo gallery (which is iPhoto on a Mac) a statement appears that says "could not complete your request because Photoshop Elements 11 does not recognize this type of file." I bought this so that I could use it on my Mac...how can I bring up my photo?
You can't use iphoto that way. The iphoto library is proprietary to iphoto's own use and trying to poke around in it from outside iphoto is just begging for trouble, the fastest way to corrupt it and maybe lose your photos. You have two main options:
1. Set PSE as your external editor for iphoto and send the photos from iphoto to PSE. Save, not Save As, and don't change the name or format and iphoto will remember the original plus your latest edited version. If you want to do that, this is the PSE editor file to choose in iphoto>preferences>advanced:
You may need to set the PSE editor preferences>Saving Files>on first save to save over the existing photo.
2. Export the photo from iphoto, make all the changes you like, then import the edited photo to iphoto as a new image.