You will need to accept the AMD license first. Open a terminal (lxterminal) and type:
cd /
tar zvxf /opt/AMD-APP-SDK-v2.4-lnx64/icd-registration.tgz
Then, for each GPU:
open a terminal
in the terminal, type:
cd /opt/miners/poclbm
python poclbm.py [options] -d [GPU number starting from 0] http://user:pass@host:port
I use -a 1 -f 1 -w 128 -v for my options