the powerCMS getting started guide will walk you through installing poserCMS:
powercms_gsg.pdf
there are 5 main steps to complete:
1) Set up the MySQL Database
2) Edit the Connections file
3) Modify the WA_Globals settings
4) Upload the files to your server.
5) Create your page content.
Instructions for competing these five steps are in the getting started guide. Please let us know if you need any clarification on the steps