Centos 5.2 How To

Hi All, New to freeradius I am needs to be said... I have been struggling for days trying to get freeradius installed on Centos 5.2 i386, I get basic pap authentication working but when i try and use authentication with mysql as the db i get errors saying "can't find module sql" when running "radiusd -X" As soon as i uncomment "sql" in "/etc/radddb/sites-enabled/default" file it starts up with no problems. I have started to rebuild the server now as I have broke it trying to fix it out of frustration. Can anyone pint me to the right place to find a decent how to? Thanks Bash