I tried to install the system... and then it said somthing about ImageMagick, I tried to install it and put that path of the software but it's doing an error... what excaclly do I need to do?
Coppermine needs to use either GD2 or Imagemagick to be able to resize images. You must have one of those installed on the server to be able to use Coppermine. If you want to use IM, then it must be already installed on the server by your host. If so then enter the path to the 'convert' program. Leave the box blank if you want to use GD.
alot of people using GD?
GD2 is a perfectly good choice. PHP must have been compiled/installed with GD2 support, it generally is on webhosts.