<<Where do I find a nice operation guide which explains the ibconfig file?>>

For InterBase 6.x and Firebird 1.0x
http://www.ibphoenix.com/main.nfs?a=ibphoenix&page=ibp_config

For Firebird 1.5, additions - read the release notes.

<<I've tried on www.ibphoenix.com... cannot find it.>>

Look harder :-)

Paul